C30 Dump needs to pull too.

[57Suburb]

I've got a 72 C30 with a dump that currently rocks a 350/th400. Nothing really wrong with the set up as it currently sits. Runs good, but a little under powered when I have a good load on. But, I want more!!! I need to be able to hook on a 20' heavy duty trailer loaded with an 873 Bobcat and up to 3000lbs worth of added payload (10k to 11k) total. I currently pull this set up around with a 93 3500 dually equipped with a 454 auto. It does pretty well, so I had my mind set on doing this motor swap into the 72, which includes swapping motor mounts and everything that goes along with it.

But, I've been thinking about an alternative of building a high torque 383 to keep everything the same, and making it a simpler swap. Seems like I can get the same torque and hp numbers as the 454, but will I be happy with it in the long run doing the kind of work I'm wanting to do? Anybody doing this heavy work with their trucks? And for all those doing the LS and diesel thing, I know they work well, just trying to keep the swap simple.

[tutone]

https://nashville.craigslist.org/pts...513113491.html

This would fill the bill and look right at home in there.

[Steeveedee]

That should be a really good deal, since he's going to have to change a lot of stuff and won't need the old stuff, like motor mounts, exhaust, etc.

[tutone]

Believe me, Im tempted. I just hate to put a motor in that's worth more than my truck.

[bs46488]

I would vote for the 454 option. How many extra things are you going to have to change in addition to the items your going to add for your building your high torque 383?

The HP and torque numbers for the 383 vs a 454 might be "similar" but the dyno charts are going to look completely different. Your going to get max torque on a 383 at like 4.5k RPM. The big block will start that torque at 2k. Which one of those will get 1 ton dump truck with 10k payload trailer moving from a dead stop (uphill)?

[Steeveedee]

Yup. There's a current thread with a guy asking how to get more low end torque with his new 383. I have a 400 BBC set up for towing- a Custom Camper- and I wouldn't mind more torque.

[crazyjeenyus]

Go with a 292, or a big inline 6. GM made a 302, they even made one close to 500 cubes I believe. Horsepower isn't your main goal here (neither is fuel economy). 292 's had close to 300 torque from the factory, probably the best stock torque to weight ratio you can get.

[D.PASSMORE]

Diesel swap or 454 BBC is the way to go. On my engine stand, putting a L31, 350 SBC with slight mods in my 70 C30 dump. Florida is flat, so cheapest and easiest way to go for me.

[57Suburb]

Originally Posted by bs46488

I would vote for the 454 option. How many extra things are you going to have to change in addition to the items your going to add for your building your high torque 383?

The HP and torque numbers for the 383 vs a 454 might be "similar" but the dyno charts are going to look completely different. Your going to get max torque on a 383 at like 4.5k RPM. The big block will start that torque at 2k. Which one of those will get 1 ton dump truck with 10k payload trailer moving from a dead stop (uphill)?

I hear what you're saying. That's the dilemma, where do I want max torque numbers. Taking off from a standing start, or when I'm going up those long hills fully loaded. The gearing in the rear would put me in that sweet spot of the 383 going up hills, especially if I kick down to second. The big block would probably be good for both I suppose.

[57Suburb]

Originally Posted by D.PASSMORE

Diesel swap or 454 BBC is the way to go. On my engine stand, putting a L31, 350 SBC with slight mods in my 70 C30 dump. Florida is flat, so cheapest and easiest way to go for me.

Man, the diesel thing intrigues me, but I'm just clueless with them. I have a cousin that's done a couple swaps for people, but I like doing things myself.

[HO455]

For low end torque and off idle pulling power inline sixes will always win. It is due to the lay out of the crankshaft giving you a power stroke of a piston every 120* of rotation. In addition they generally have longer stroke to bore ratio, than a V configuration engine, which increases torque. The downside of this is reduced RPM capability.
A gear spilter such as a Gear Vendors O/D will make pulling hills easier on the engine as you can keep it in the lower end powerband and still maintain your speed. Swapping in a two speed rear end would help in this if you can locate one.

Drop in on the diesel side of the board and take a look around. Dieselwrencher's build thread is full of information.

[57Suburb]

Originally Posted by HO455

For low end torque and off idle pulling power inline sixes will always win. It is due to the lay out of the crankshaft giving you a power stroke of a piston every 120* of rotation. In addition they generally have longer stroke to bore ratio, than a V configuration engine, which increases torque. The downside of this is reduced RPM capability.
A gear spilter such as a Gear Vendors O/D will make pulling hills easier on the engine as you can keep it in the lower end powerband and still maintain your speed. Swapping in a two speed rear end would help in this if you can locate one.

Drop in on the diesel side of the board and take a look around. Dieselwrencher's build thread is full of information.

LOL, maybe I should just ask Dieselwrencher to install one for me. He's just down the road.

[HO455]

With a resource that close it would be hard for me to not go oil burner if I was in your shoes. Buy him lunch/beers and talk about it. He's lucky I live so many states away.

[AK49Watson]

No love for the 400SBC... 400ft lbs torque at 2400RPM. Stock.

[HO455]

In this application no. The heavy hauling/towing the OP is looking to do is where the 400's reputation as a weak engine started. Any degradation of a normally adequate cooling system and those engines will overheat, usually fatally.

[AK49Watson]

Originally Posted by HO455

In this application no. The heavy hauling/towing the OP is looking to do is where the 400's reputation as a weak engine started. Any degradation of a normally adequate cooling system and those engines will overheat, usually fatally.

Nah, throwing heads on without steam holes and blocking bypasses is what started that myth.

[Steeveedee]

Originally Posted by HO455

In this application no. The heavy hauling/towing the OP is looking to do is where the 400's reputation as a weak engine started. Any degradation of a normally adequate cooling system and those engines will overheat, usually fatally.

In '71, GM started putting two-row radiators in cars equipped with SBC 400s. I kid you not. I've seen them come in on a string with blue torque converters. This is where that reputation started. Chevy ate a ton on those engines because of that engineering debacle, and retrofitted a lot of bigger radiators in those cars. Once the spanking was complete, GM went back to a decent radiator. My dad's '75 Caprice convertible equipped with a 400 CI SBC and AC had no troubles whatsoever in southern California. It had a 4-row radiator.

[57Suburb]

Originally Posted by AK49Watson

No love for the 400SBC... 400ft lbs torque at 2400RPM. Stock.

I've done the 400 thing. Built a 408 for this.

She is stout, and I love the torque, but guess what, have had a little trouble keeping her running cool when idling around at slow speed.

[Richard2112]

I've been thinking about this same thing for a while now. Though my C30 doesn't need to pull, I would like to know that when the day comes to tow, I can.

I read an article about a dyno'd high torque 383 but still wonder about the actual street performance.

http://www.hotrod.com/articles/gm-ht...block-tune-up/

Those are some impressive numbers for pulling power. Been considering the I6 also. Haven't thought much about diesel as I heard the weight can be an issue but the torque is certainly there.