I am in the process of designing my rock crawler engine.
I have always been a sbc guy, but all I know is how to build for HP. I need tips on building for torque.
I am starting with a mid-80's 350 4bolt main, it is going in a light full-body crawler and will be propane injected.
I would think a heavy flex plate would be a starting point, but from there I get lost.
Please help.

I am in the process of designing my rock crawler engine.
I have always been a sbc guy, but all I know is how to build for HP. I need tips on building for torque.
I am starting with a mid-80's 350 4bolt main, it is going in a light full-body crawler and will be propane injected.
I would think a heavy flex plate would be a starting point, but from there I get lost.
Please help.

id look into building a internally balanced 383stroker, i loved mine!

I'd definately go a lot of cubes. Vortec heads, Extreme 4x4 cam, or another cam spec'd out by a good cam company. 383 rotation assemblies are going pretty cheap now. If it's for a crawler, you're probably not going to turn it a lot of RPM's. I'd get one of Eagle's cast crank 383 kits. Like this: http://cgi.ebay.com/ebaymotors/Eagle-INT-Balanced-383-Rotating-Assembly-KIT-SBC-SALE_W0QQitemZ120058068900QQihZ002QQcategoryZ33620 QQrdZ1QQcmdZViewItem
If you want internally balanced. Or this:http://cgi.ebay.com/ebaymotors/Eagle-Balanced-383-Rotating-Assembly-KIT-SBC-SALE_W0QQitemZ120060748502QQihZ002QQcategoryZ33620 QQrdZ1QQcmdZViewItem
If you want externally balanced.

compression and displacement
extreme cams have a fast lobe, I wouldnt run one. if you need the fast lobe go roller.

so higher compression builds more lower rpm torque ??

then why did truck engines(called hi-torque by factory) always have really low compression ratios

im talking in the 1960s and 70s especially, with the 307, 327, 350, 400 engines

vs. the turbo fire car engines in which were usually higher compression but alot lower torque rated

im confused ?

so higher compression builds more lower rpm torque ??

then why did truck engines(called hi-torque by factory) always have really low compression ratios

im talking in the 1960s and 70s especially, with the 307, 327, 350, 400 engines

vs. the turbo fire car engines in which were usually higher compression but alot lower torque rated

im confused ?

Truck engines were expected to run on cheap gas, and to run for hundreds of thousands of miles with out a rebuild, and to be run a full throttle most of the time. To build an engine like that you need to think of how to fill the cylinder at low RPM's. Pick a set of heads with smaller runners to keep the intake velocity high at low RPM's, a set of Vortec heads off of a pickup would work good. Smaller valves could be a good thing too, a stroker crank would help low end torque as well. When you pick a cam, you want something with very little overlap. On the exhaust side, you again want to keep the velocity high at low RPM, smaller tube headers are the way to go, or even some tri-Y headers. Try to keep the quench as small as possible, it helps keep detonation down.

Try to go for a 383. Keep it around 9-10:1 compression and your golden. You want to run pump gas for sure. Run some vortec heads and a simple injection system, throttle bodys are awesome for building torque and very simple. You want to keep this motor as close to what parts stores have on the shelves as possible. Its pretty easy to make nice torque figures off a smallblock using a mild build plan.

Tbi, vortec heads, a truck cam of whatever flavor you want (most decent cam makers have a pretty good idea of what you want), a little bit extra displacement and some tuning and your good for 300 horse and 400lbs. There are always boltons too, electric fans, headers, etc...

read the post, he said propane not garbage gas, so that dictates 11:1

Propane? Go for the compression for sure. As already stated above a 383 is easy and cheap..comparatively. Good compression, cubes and a mild build (low dur. cam) and you'll have a pretty torquey SBC. Smallish ports on the cyl heads like 170-180ish, 1.95/1.50 valves, dual plane intake like an Edel Performer with smallish runners.....keeping intake velocity high promotes good fuel atomization/mixture and a "ram" effect. Smaller tube headers or Rams horns will be beneficial to keep exhaust velocity up as well for decent scavening

Thanks for all the help.