Results 1 to 15 of 15

Thread: I need more chevy grunt....

  1. #1
    Senior Member Sr. Forum Member
    Join Date
    Aug 2004
    Location
    Lancaster
    Posts
    2,311
    Rep Power
    20

    I need more chevy grunt....

    Im looking to get alot more power from the hualer.... when empty the stock 350 cant get out of owns own way, laoded there is NO way I can make the climbs to Kentucky/TN/NC

    Keep in mind this is a 77 GMC, wedgebed that empty wieghts 8200 pounds, and pushes over 10k once the rig and tools are laoded in. I do plan to convert alot of the non structural steel in the bed to aluminum ( doors, sides ect.... )

    Whats going to be the most cost effective way to gain some.
    Things I have thought of:

    Simple overhaul with an RV cam and a shift kit for the TH400. and maybe replacing the quadrajunk with a holley.... Any tips for what shift kit I'd want? Its got a manual valve body from the factory.

    454? Coslty to buy so to fit in my budget it probably just get an overhaul and remain stock, with the addition to the th4000 shift kit.

    Any other "cheap" options.... Diesel would be nice but no where close to the budget.

    I'd like to spend $1000 or less in doing this if possible.

    I would also like to go to disc rear. It has a Dana 60 swapped in, but I have a factory 14bolt I could put back in if needed... both are dual wheels. Which would be easiest to disc and what parts would I use? I dont like the idea of stopping 10k with drums on the back....

  2. #2
    Local Goon Ohio 4x4 Member
    Sr. Forum Member
    tbshakie's Avatar
    Join Date
    Nov 2003
    Location
    Circleville
    Posts
    1,410
    Rep Power
    22
    If you wanna keep the 350 I can give you some recommendations. VORTEC HEADS. bolt on 40 hp with better efficiency and higher compression. i paid 228 a head for mine out of soggin dixie (sp) in texas. you wont even know it is the same engine. thise heads require a vortec intake. so add that to the cost. throw in a good cam and you will have loads more power.

    10K is pretty heavy so a 454 may be a viable option. Wonder how much you could pick one up for. will bolt right up to your tranny.
    Paul

    1976 CJ 5 on 37s
    1984 CJ 7 on 36's
    1993 GMC K3500 6.5 Turbo Diesel

  3. #3
    Senior Member Sr. Forum Member
    Join Date
    Aug 2004
    Location
    Lancaster
    Posts
    2,311
    Rep Power
    20
    Egay shows 200+ for block with heads for the 454.....

    My buddy has one I MAY be able to get for a decent price.... had a th400 behind it in a 50foot motor home so im sure it would have some grunt after a rebuild.

    I could probably build a decent small block for pretty reasonable. The cousin runs pure stocks at the local circle track and stocks up on parts and has sponorship deals with some places that do machine work.... Probably has a .30 over block laying around I could start with......

    I hate to spend big if not needed, tempted to pull it and rebuild it with mild cam and better heads... 202's or something??? port and polish it, add headers... and maybe gear the rear down a notch... I dont think im gettign enough rpm to reach peak going down the road.

  4. #4
    Moderator/Life Member Moderator
    Sr. Forum Member
    Roy's Avatar
    Join Date
    Jun 2003
    Location
    Philo, OH
    Posts
    5,665
    Rep Power
    30
    A built 350 will run circles around a stock 454...when it comes to racing. Torque is what is required when towing. Many 350 Chevy, 351 Ford, and 360 Chrysler small block engines can make 400+ ft. lbs. of torque...most often this max torque figure is above 3500 rpm. 3500 rpm is not an ideal cruise rpm.

    What is important is to pay attention to what torque the engine will make at your towing/cruise rpm.

    I built a 460 for the off-road truck to maximize low rpm torque. I tried many camshafts on the DD computer simulation program. I was looking for maximum torque in the 2000-2500 rpm range. Top end HP means nothing if the engine can't "pull into it's powerband." Torque at 2000 rpm meant more to me than having a massive HP/TQ output at 3000-5000 rpm. Why? Because the engine will spend most of it's life between idle and 2500 rpm.

    Large cubic inches, stock compression (it will run on 87 octane) and maximum low rpm torque are the principles on which I am basing my future tow rig 460 engine.

    On paper, the engine will make 500 foot pounds of torque at 2000 rpm, and 310-320 HP at 4000 rpm. The HP output is quite pathetic for the size of the engine. HP means little to me in a tow rig. It should be noted that I am far from a professional engine builder, I'm not ASE certified in anything, etc. In my years with this club, I have had to have Buford towed home twice.

    The first time was in the winter of 2004. After a wheel bearing failure, I stopped at a gas station in Lancaster, and had the truck towed home on a Dodge 3500 series rollback with the Cummins Diesel. I was impressed with how it towed the Ford home on a simple 1-ton rig. The driver of the rig rarely had to downshift out of 5th gear (5 speed manual) on the way home.

    The other time I've been towed home was in mid August, 2005. This was on a 1999 Ford F-550 rollback. It had a generic 235 HP/500 ft. lbs. of torque engine according the the driver (owner of the company). This rig was also a 5 speed, and the only time we went real slow was when he was purposefully slowing down on steep, windy, hills. I was asking many questions about the power, etc, on the ay home, and he noted the Powerstroke powerband started at either 1600 or 1800 rpm...and when the engine fell below that rpm, it fell flat on it's face.

    Regarding the HP vs. TQ debate, look at the Ford 7.3 Powerstroke (turbo) Diesel engines...when they came out in the early-mid 90's, they were rated around 235 HP and 500 ft. lbs. TQ. A stock 5.0 Mustang GT at the time had 225 HP, and 300 lbs of TQ. Which engine would be better to tow with? It's obvious. The point of all this blabber on my part is that TQ is more important than HP when towing.

    Roy
    Large: 1978 Ford F-250
    469 V-8: 340 HP, 525 TQ
    C6, NP-205, 4.10's, 42" TSL's on 15x8's
    D60: Detroit, 35 spline Alloy Shafts w/ Longfield Superjoints, Dedenbear Knuckles, Drive Flanges.
    1410 Driveshafts, D70-U Welded, 12K Winch, OBA.

    Small: 2009 Yamaha Grizzly 700 4x4

  5. #5
    Member Forum Member crazi429's Avatar
    Join Date
    Oct 2005
    Location
    Brookville Ohio
    Posts
    286
    Rep Power
    15
    find yourself a old beat up caddy with a 500 and turbo400 and drop it in thats my plan when ever the 454 in motorhome dies
    keep up or get left behind
    75 bronco trail buggy
    60-9 frt build up thread
    My pictures
    email =haspinpic@aol.com
    password=flatbroke
    OutBack Auto 4WD and Fab
    MV4W.com

  6. #6
    Moderator/Life Member Moderator
    Sr. Forum Member
    Roy's Avatar
    Join Date
    Jun 2003
    Location
    Philo, OH
    Posts
    5,665
    Rep Power
    30
    Quote Originally Posted by crazi429
    find yourself a old beat up caddy with a 500 and turbo400 and drop it in thats my plan when ever the 454 in motorhome dies
    That's a good idea...cheap and effective.
    Large: 1978 Ford F-250
    469 V-8: 340 HP, 525 TQ
    C6, NP-205, 4.10's, 42" TSL's on 15x8's
    D60: Detroit, 35 spline Alloy Shafts w/ Longfield Superjoints, Dedenbear Knuckles, Drive Flanges.
    1410 Driveshafts, D70-U Welded, 12K Winch, OBA.

    Small: 2009 Yamaha Grizzly 700 4x4

  7. #7
    Moderator / Life Member Moderator
    Sr. Forum Member

    Join Date
    May 2003
    Posts
    3,544
    Rep Power
    2120
    Never seen a factory manual valve body transmission before, but that doesn't mean they don't exist. So you have to manually shift the gear selector as you drive (start out in 1, shift to 2, 3...and then downshift gears as needed) correct?

    As mentioned before the proper gearing setup will help (don't know what you have now though). A 14-bolt probably is not a bad idea as it should have a higher weight rating than a Dana 60. For gearing, I'm guessing you probably don't want to go any lower than 4.10 assuming a stockish 30-31" tire because with no overdrive you will be cruising at 3,000+ rpm at 65 mph.

    If you have a dually version 14-bolt it should already have the bigger brakes (two different sizes available on the 14-bolt). For something driven on the street you really shouldn't have any problems with the stock drum brakes. It's not that the rear drum brakes don't work okay, it's just that disc are definitely better for off-road use simply because you don't have the mud and water issues. If you convert to disc you will also lose the parking brake unless you go with a newer style setup, and I think a parking brake is nice to have on a really heavy truck.

    Yes, engines that make big torque numbers at your intended cruising rpm are ideal and the best bet. However if properly built a higher revving small block could work okay, you just have to make sure you use the right parts to keep it together while spinning 3,500 rpm or so for extended distances if needed. My tow rig makes a relatively small 360 ft-lbs. of torque, but it also has 300 hp and could spin over 3,500 rpm from here to California and back with no problems. Get much below 2,500 rpm and it's dogging pretty bad but it feels strong at 3,000+. I've driven stock mid-80's trucks empty and loaded with big blocks and they were dogs, I'd rather have my newer small block than those. Of course the newer big blocks or diesels would have been nice in my truck but I wasn't willing to take the cost and mileage penalties assosciated with that.

    Your stock 350 was probably a pretty anemic 150-160 hp and mid-200's torque stock, and add in lot's of wear and I'm sure it's lower than that now. I'm sure a freshening of the engine and some good parts of the existing 350 would make a huge difference, though a big block with the same parts would be even nicer.
    Brad
    '90 Blazer - 6.2 diesel, 700r4, Dana 60, 14 bolt, locked, 39.5" Super Swamper TSLs, winch, rollcage, yada, yada, yada......

  8. #8
    Senior Member Sr. Forum Member
    Join Date
    Aug 2004
    Location
    Lancaster
    Posts
    2,311
    Rep Power
    20
    My parking brake is line locks, there are no cables and try finding 25foot long cables...lol

    I like the disc becuase I have a tenadncy to ride the brakes.... (been i nTWO rear end collisions cuased by me so im parionoid) I eat rear shoes up very couple of months in anything i drive.... not to mention adjusting brakes on an 8200 pound truck thats 10 inches off the ground i nthat area is a pita

  9. #9
    Senior Member Sr. Forum Member
    Join Date
    Aug 2004
    Location
    Lancaster
    Posts
    2,311
    Rep Power
    20
    .ps.s I think I found my 454..... FREE 14foot chevy cubevan with 454, realtor buddy bought some property and its sittin there.... siad I coudl have it!

  10. #10
    Moderator Moderator
    Sr. Forum Member

    Join Date
    May 2003
    Location
    Marengo
    Posts
    1,045
    Rep Power
    20
    Gears are pretty important for giving it the torque. A hillbilly mod if you feel like trying it out is to install chevy 305 heads on the 350. You can get them for $20 each at U-Wrench-It. This will give it 40 or 50 more HP, but you need to know that the engine has not been rebuilt before because the clearances will be close enough that if the block as been modified much the valves will contact the pistons. You should be able to get some power just by installing a nice intake, cam, and tuning the carb correctly.

    Evan
    `92/79 Toyota Blazer 350 engine, TH 350/NP203, fullsize axles, 38.5" boggers, bed mounted John Deer radiator, onboard welder.

    Army M35A2 "Duece and a Half" 6x6 cargo truck

  11. #11
    Moderator/Life Member Moderator
    Sr. Forum Member
    Roy's Avatar
    Join Date
    Jun 2003
    Location
    Philo, OH
    Posts
    5,665
    Rep Power
    30
    This is a myth. Stock 305 (58CC) Chevy heads on a stock 350 will not add 40-50 HP. The smaller combustion chamber (CC) will raise the compression, but the 305 heads have smaller valves (among other things) and are prone to detonation (pinging).

    Roy
    Large: 1978 Ford F-250
    469 V-8: 340 HP, 525 TQ
    C6, NP-205, 4.10's, 42" TSL's on 15x8's
    D60: Detroit, 35 spline Alloy Shafts w/ Longfield Superjoints, Dedenbear Knuckles, Drive Flanges.
    1410 Driveshafts, D70-U Welded, 12K Winch, OBA.

    Small: 2009 Yamaha Grizzly 700 4x4

  12. #12
    Senior Member Sr. Forum Member
    Join Date
    Aug 2004
    Location
    Lancaster
    Posts
    2,311
    Rep Power
    20
    Yeah, definitly will not put 305 heads on my 350, if I do anything over a stock head I'll stick on some 202 heads and be done.

    Here is the plan thus far.

    simple rebuild (gaskets rings...etc) with an RV cam, rebuild the qjet to of course, factory tubular manifolds, and be done with it engine wise.

    For the th400, I'll put a rebuild kit and shift kit in it.

    The truck itself is getting the ford 60 that some idiot put in becuase of "lower" gears which actually has 3.55's removed and the correct 14bolt with 4.10's (which the truck had factory) The all steel wedge bed is getting chopped, and lowered so that it runs parrallel to the ground just above the rear wheels with a 4foot dove at the rear. The sides of the bed will be replaced with aluminum. I have a 24foot motorhome all stock with 66k on her same set up as the hualer engine/tranny wise, but its got the RV cam obviously and still has the stock 4.10 gears 14bolt.... it manages about 10mpg running out the interstate and wieghs in at 2k over the hualer at 10200.
    I'm hoping by giving the hualer the identical drivetrain and lighter wieght (probably a good 1k lose of bed wieght after I redo it), I can mange about the same speeds/mpg as the camper does once the hualer has my rig on it.

  13. #13
    Member Forum Member crazi429's Avatar
    Join Date
    Oct 2005
    Location
    Brookville Ohio
    Posts
    286
    Rep Power
    15
    my 80 cc dually has a 350 4spd and 3.73 dana 70hd rear end and I get 12mpg out of it the motor is a 78 350 stock bore freshened up with 194 heads and a comp cams 268 rv cam stock carb and ign and headers w/ dual exhaust
    as for tires it has 8.75x 16.5 so they are short compared to the 235/85r16 on my motorhome
    it doesn't win no races but it can pass some gas stations
    my trailer less bronco weights 3800 and bronco weights 5400
    so I am hauling heavy but it gets the job done
    now the motorhome has 454 t400 and 4.56 14b and I won't check the mileage on it since it probably is around 5 or 6 but is pulls the trailer much better and it to can pass a gas station or 2 but thats because of the 80 gal fuel tank
    keep up or get left behind
    75 bronco trail buggy
    60-9 frt build up thread
    My pictures
    email =haspinpic@aol.com
    password=flatbroke
    OutBack Auto 4WD and Fab
    MV4W.com

  14. #14
    Junior Member Forum Newbie
    Join Date
    Apr 2007
    Posts
    5
    Rep Power
    0
    The vortec heads are worth the money i love them.

    Mudking
    1979 cj-5 chevy axles,350,4-speed.205


  15. #15
    Senior Member Sr. Forum Member
    Join Date
    Aug 2004
    Location
    Lancaster
    Posts
    2,311
    Rep Power
    20
    Dang this is an old thread

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •