Towing setup questions

[bulkin'up73chevy]

New truck. 78 long bed t350 trans. I will be towing an 8000 lb. fifth wheel. right now motor is stock and can't move the thing worth squat. I am doing all the standard towing stuff that I can think of.

Upgrade tranny cooler.
Bigger radiator.
MSD ignition.
Heavier running gear.

I'm trying to get a good motor setup.

I'm thinking stock crank
flat top pistons.
edelbrock two plane manifold
I understand the stock carberator can get more torque than an bigger with jets is that right??
I have 194 heads (possible port these??)
bore motor out .040
280/280 cam.

what would be a good comp. ratio for this.

or am I completely off of where I should be??

[Prong]

If you moving that much weight on a regular basis, I'd be looking for a 454/TH400 to go in there.

[James McClure]

Prong is right. Towing needs torque not RPM. Get a hog block and build a good 400 to go behind it. You won't get any gas mileage either way. Less than 10 or 11 mpg.jim

[boatpuller]

your rear end ratio is a huge factor in towing.make sure your not under powered back there,it can make more impact than anything.and,i see your a fellow s.w guy.there's a few of us around.in fact in the regional section weve been kickin around a meet this summer for the greater portland/s.w washington area guy's.

[Pyrotechnic]

Since you are considering building a motor, I wouldn't even consider a 350. Step up to a 454.

Also, the Cadillac 472 and 500 are worth mention. Not a bolt in swap, but members who have done the swap have said that the towing performance and gas mileage were great.

[mrmojo32]

WHat is the rear gear ratio? As Boatpuller said, that can make HUGE difference.

[78 Big10 454]

My vote is for the 454/400 set-up. I run that combo in my truck and I can fly down the freeway towing 8,000 lbs. like there's no tomorrow. Gas mileage sucks, however, whether you're towing or not...

[79blazer]

Stroke it, make it a 383 stroker. Basic intake, Vortec heads and RV cam, shorty headers, 3 inch or dual exaust, 3.73 gears or lower unless you are using oversized tires. Tuned quadrajet or edelbrock carb

[bulkin'up73chevy]

4.10 gears under thirty three's I blew out my rear end in the recent snow, pulling people out get some spin going then hit dry pavement. I want to get back to my 3.73's but i'm thinking the 4.10 is going to be better for towing. I don't move this thing on a regular basis and eventually I will be getting a newer diesel just for the thing. Unfortunately the economy but that idea in the hole pretty quick. what's a good combo for torque just to move it on occasion. I did take a look at a 88 crew cab one ton with a 454 but if I don't get that then this is my truck that will have to do it.

[charlie diaz]

if you already have the 350 and the 194 heads, then get a stroker kit and put that in there. If the 194 heads are the Vortecs, then they should have a 64cc combustion chamber that will help bump up your compression. You wont need to go with flat top pistons. A dish pistons hooked to a 400 crank with 5.7 rods will give you compression of 9.5:1. I would think that this and 4.10 gears would be plenty for the "occasional" tow. Car Craft built a motor like this a while back and it was good for 440 lb. ft. of torque a@ 3000rpm. Hell, @ 1800rpm, it had over 300 lb. ft. of torue. That should do you right.

[bulkin'up73chevy]

What was his cam selection?? The reason I said the 285/285 cam is i downloaded the comp cam's program and I would be pushing 416 ft/lbs torque and 330 some horsepower. Does that sound right?? Does he have a post of his motor build would love to read it. Unfortunately these are not the vortec heads however porting and polished them should get about the same performance right??

[andrewmp6]

Engine size really don't matter its how much torque it has down low.You want at least 75% of the torque under 3k rpm.You might want to run a oil cooler and on the tranny cooler get the one with the fan on it.Both are cheap insurance.

[red caddy]

You can flog that SBC, and spend a ton of money, doing the things suggested (all of them will work to some extent) But engine life will be short and driveability will suffer. You are just asking that little small block to do things it was never designed to do.

A 454 and TH-400 will give all the power you need, but to make the best use of it, a gear change will be required (3.50's) or you will be screaming down the road at a high RPM most of the time and mileage will suck. My '77 suburban got 7-8 MPG towing a 26 Ft boat and 11-12 MPG around town with the stock 4.10's.

A "shift on the fly" overdrive (gear vendors) will really help the open road towing MPG, but at around $2500.00 the payback time is long and the performance around town in OD is not stellar.

The best "non diesel" tow rig I ever had was a '74 long bed with a 500 caddy/TH-400 pulled from a sedan deville. The swap is easier than you might think, extend the motor mounts forward about 5 inches and modify the tranny X member slightly. There are some oil filter clearance issues, but they are easily solved with a remote cooler/filter setup. With 3.50 gears and 32 in tires, the towing Mpg was 12-14 and 16-18 around town. the only engine work done was the addition of an Edelbrock 2115 intake w/rebuilt QJet and eventually, a set of BBC long tube headders modified to fit the caddy. The engine had 40 K miles on it when I dropped it in (changed the timing chain and water pump, looked at the rods and mains, cleaned the pan and valve covers while it was out and easy,LOL) and 178K when she was killed by a drunk driver. Pretty good payback for the money and time invested. RED

[bulkin'up73chevy]

This motor is really just a temporary thing till I can get my diesel but by the sounds of it, I should just use my flatbed, until I invest in the diesel. That's fine. So now I can move on to the build I want. The motor specs I gave at the beginning. Would that be a good streetable motor with power to spare, and good over 4.10's and 35's?? I'm ready for the six inch lift and ready to pull the motor. Is there a part on there that won't match up for some reason?? Please tell me cause otherwise i'll be moving forward with the build soon.