My buddy and I just bought a 78 Chevy 1/2 ton 4X4 pick up. We got it for $750.00. We are going to use it as a parts hauler, potential tow vehicle, and also share it for all the things you use an old pick up for. It has a 350 and a TH350 trans. The motor only has 78,000 miles on it but the PA winters have taken their toll on the body. OK this leads me to my question...

We want to freshen up the motor a little. All we want is to use a mild cam and get rid of the 2bbl in favor of an aluminum intake and a 4bbl. I have looked at Summit and Jegs and seen some mild cams that are priced nicely. My question is what kind of lift and duration can abone stock 78 350 handle without changing valve springs? We really don't want to begin sinking a ton of money into this truck. All we want to do is to yank out the stock cam and intake and replace it with a very mild cam and a 4bbl for towing or hauling purposes. Any help would be appreciated.

Buy some springs.
The Z28 spring will support about .500 lift & is a drop in & they are only about 25-30 bucks a set
The only thing you need to watch on your engine is the exhaust valve spring height.
It should have rotators which look like thick retainers.
There are two different stock springs, & GM did the heads two different ways.
One the exhaust springs will be about 1/8" shorter than the intakes & all you need to do here is get a set of stock type intake retainers as the head is cut the same both intake & exhaust at the seat.
The other is the springs will all be the same length & the seat will be cut deeper. You will need to use the rotator exhaust retainers (not really recommended) or install a spacer under the spring to get the installed height right.
About 1.700-1.750 installed height will be fine.

Ok I hear what you're saying. It sounds to me like with this job we might get into pulling the heads. We were kind of trying to avoid that. I know that neither of us has a valve spring compression tool. All we really wanted to do was stab a mild cam and a new timing chain in there and throw on an intake and a carb and go. We still have to do some body work to fix the rust, plus it needs a new set of tires as well. We just wanted to avoid going nuts spending money on this truck. I know how easily one small job can turn into a bigger one.

Why not throw a cast iron GM intake and a quadajet on it, then you can save your money for the parts you want to haul in it. graemlins/thumbsup.gif