In the process of putting a '79 GMC ShortBox back on the road. I have a '70 350 (<80K from a Cutlass Holiday Coupe) to install. The motor is bone stock - never rebuilt; compression is real good, bores are smooth. Has #7 heads, no intake/carb, no exhaust manifolds. (I have a 411880 intake in the shop)

I'm like to hear some advice on what to do/have done on this motor to make this truck a fun daily driver; decent performance, decent mileage.

I have a 455 that could really take the truck to the edge and back - not really wanting to do that with this project.

Looking forward to what you all would be thinking if this was on YOUR project list.

Thanks.............

 

You could just throw on a Edelbrock 7111 manifold, decent carb (probably around 650 CFM and cheap headers and dual exhaust.

Won't be a powerhouse, but will be fun to drive

 

Is what you have a diesel short engine (block, camshaft, crankshaft, rods & pistons)?.

If it still has the diesel camshaft, pistons and rods that might be a problem as the pistons come past the top of the bores, giving you issues with too much compression for pump gas and valve clearance. The camshaft may be unsuitable for a gas engine too.
It's not a simple case of putting in gasoline pistons, the diesel rods are shorter than 350 gas ones and the the crank journals are the same size as big block ones too.
Swapping the camshaft should be simple enough though.

I think there are some old threads on how to convert a diesel to gas, maybe someone can direct you to them.

It might be simpler to put a 455 in instead, depends on what it will cost to modify your 350D. Having said that a converted diesel will be pretty well bombproof.

Good luck!.
Roger.

 

I would just go Q-jet on a stock or ebrock 3711 intake and duals if keeping the '70 350 stock. Keeps with your decent performance, decent mileage comment. What transmission and rear end is in the truck?

 

Hang onto the diesel block..great for 350 builds.
For an economy build,your thinking the correct way,going with the 350.
Better mileage,decent performance,easy swap.
Building an engine is a different story,as most engines cost nearly the same to build,depending on what your starting with.
Crate motors are a nice deal at $1500 also.

 

Someone correct me if I'm wrong but I think 70 was the last year for the high compression 350? If so assuming you know its a good runner you might just consider an intake, cam, and a mild carb to your taste (rochester, holley, edelbrock are all great carbs). I have just about the same truck (75 chevy c10) and if I had the motor in question I would probably just drop it in and go from there. These olds 350's are very torquey and should be fun in the truck.

I put a lot of work into my chevy 350 that I just dropped in my truck and it is STILL a dog on account of a tired th350 trans, stock converter, .308 peg leg axle ratio and 33" tires. I would have benefited a lot more from a gear swap than I did from the Dart heads I installed... However I built the motor on a stand without any specific car in mind and had to use it out of necessity. So just bear in mind that there are a lot of other things that can hold that motor back.