The Stovebolt Site Forums The Shop Area Engine Shop Need hadvice on "warming-over" a '78 350ci

Well, with posts like fuel/air velocity calculations, this question should be easy! Anyways, just bought a 78 chev PU donor truck to transplant motor, trans, few other parts in my 54 chev pu. What I would like to know is, what is the most efficient and cheap way to "warm-over" this engine? I have a low budget right now, so gaskets, spark plugs, basics, got it. But anything else? New cam? New timing chain? I dont know, so please help. It runs great for an old truck, still kicking pretty hard actually. Looking for this to be my daily driver. Thanks!

welcome to the garage JM, we'll be waiting for the story in the Welcome forum and some pictures, we like pictures

get an overhaul gasket set, check and clean everything you remove to replace those - get a new oil pump, water pump, and timing set ... if it all checks out inside you're good to go

Bill

Stage 1. If you are looking for some more HP, go to a cam, lifters and timing chain. I just put in a CompCam High Energy cam, timing chain, lifters and spring kit and I liked the response. Use that old HEI ignition too with new cap, rotor, wires and plugs. Don't spend too much money on plugs. Use original numbers that came with that engine.
Stage 2. If you want to spend more, go with an intake manifold. An Edelbrock RPM, or a WEIAND Stealth would be good.
If you have a "good" Quadreajet...keep it. Otherwise, try a 600 CFM carb. If you go too much bigger you will loose low end performance.
Any stage. If you want to really help what you have in all areas, put in a dual exhaust with a crossover pipe. Headers would be an addition, but they will create more noise (sound) inside too. At any stage, dual exhaust will sound good. It will make you think its hot even if it is not.

If you are going to pull the oil pan off, Might as well check the main bearings and rod bearings too.
If you are going that far, you might as well at least re-ring it and break the cylinder glaze.
If you pull the heads, might as well lap the valves and put in new valve seals. They would come with a cam, lifters, springs and timing chain kit.

Get a couple of cans of chevy orange engine paint too. You are going to want it to look good.

That is the order I would choose to do things if I could only do one or two. An exhaust will sound and perform good at any point though. The most immediate HP will be with the cam kit.

You could also put on some iron vortec heads and intake. That can be a 20-40hp gain. I could spend your money all day too. Maybe you just want a good tuneup and oil change. lol

Good luck!

Ditto to all the above. A Comp Cams 268H High Energy cam is about the max a stock-compression street engine can handle without adding a lot more go-fast stuff. Use the reccomended anti-pump-up hydraulic lifters and valve springs to go with it. It will handle 6,000+ RPM without floating the valves that way. Use a roller-type timing chain and the corresponding sprockets, along with a thrust button that keeps the cam from "walking" back and forth and changing ignition timing a couple of degrees by varying the distributor gear rotation. Restricting the centrifugal advance in the stock HEI distributor by about 5 to 8 degrees and adding the same amount to initial timing will give you a better holeshot without creating excessive timing advance on the top end. I like 2 1/2" exhaust pipes and Cadillac mufflers with both inlet and outlet pipes the same size. One muffler can handle a 500 cubic inch Caddy engine, and dual pipes with those mufflers are quiet, and act like straight pipes where back pressure is concerned when paired up with a 350 engine.
Jerry

Jerry, What years are those mufflers used. I remember reading of that years ago in HotRod or the like.

Early to mid-1970's, behind 472 and 500 cubic inch engines. They have 2 1/2" inlet and outlet pipes. They're fairly long, but the flow rate is great, espsecially on smaller-displacement engines. I set up my son's Dodge pickup with a 318/Torqueflite running gear that way, dual pipes and mufflers with the 2 1/2" tailpipes and 3" bologna-sliced tips. It was quiet, but fast. I used the Comp Cams 260 High Energy cam in that one with a Carter AFB.
Jerry