I'm going to put together a 350 out of parts I have laying around, and it will go in a Camaro that is also going to be put together with parts I have laying around, so the goal here is CHEAP FUN.

The base will be an older GM crate 350, that currently has the stock heads on it. I think it is the 260 horse model. I also have a ported set of '450' casting 305ci heads and a set of 350 truck swirl port heads. All of these heads are in good condition, but new valve seals would be installed because they have been sitting. I also have a set of '416' casting 305 heads that are in unknown condition.

What would you run? This will be a street car that will likely be sold after I get it back on the road.

 

I think the 450s are the LG3 heads, with 1.72" valves. I'd take the 1.94" valves out of the crate heads, and take the 416 heads to the machine shop to be cut to fit the 1.94" valves. First a 30 degree back cut to all 16 valves, then the 3-angle valve job, then a 75-degree bowl hog, then a de-shrouding sweeper cut for the intakes.

 

The 450's are late 70's heads with the 1.84 or whatever valves. They were on the 350 that was in one of my Camaros when I got it. It felt strong for a stock (well, sorta) TPI motor and had very little miles on it. I really don't want any machine work, the goal here is to spend nothing, or close to it. The 416's are probably OK, they came on a high mile '86 Z28 parts car I had. It was an lg3 car, but I'm guessing the heads were not original to it.

 

416s are LG4 heads. They're supposed to be 58 cc. LG3 heads are supposed to be 60.6 cc The 416s will have the extra hole necessary if you're going to use any third-gen exhaust manifolds. double check the valve sizes in the 450 heads. LG3 was '76-'79, with 1.72", while LG4 was '80-'87, with 1.84" Only the '76 heads were heavy casted. All '77-up heads were light, thin castings. You can spot them by the scallops. BTW, these crate heads, are they centerbolt or perimeter bolt valve covers?

 

The crate heads are perimeter bolt style. I think it was purchased in '95 or so.

I'm fairly certain the 450's have the larger valves. Although since they are ported, they obviously have been worked on, so maybe they were installed. I think they have the extra bolt hole for the manifolds, I'll check. I do plan on running a set of manifolds from my '86 TPI, and hoping they work with the stock '84 HO y-pipe in the car.

Oh, I said LG3 earlier, I meant LG4