I have a problem now and would like some advice.. I have a 89 trans am with TPI. I rebuilt a 71 or 72 350 and put the TPI on it, seems that the TPI intake doesn't lone up with it? The two center bolt holes on both sides aren't lined up right? Common problem? Also, it seems that my serpentine system doesn't match up to the bolt holes on the heads? I got to looking and comparing them to my old heads and it looks like I might have two left or two right heads on the engine, how can I tell for sure?

 

No such thing. The heads should be identical.

There are however different intake manifolds. Early manifolds/heads, the intake bolts are angled and go straight into the head. Late model manifolds/heads, the intake bolts are vertical and go straight down.

To use a late model intake on early heads, the mounting holes through the intake manifold need to be modified.

 

On one heads there are 3 bolt holes in the front, which seems right. But the other one has the 3 bolt holes on the back of the engine.. Which is what is making me think something is wrong?

 

Maybe you have a older head and a newer one. pop the valve cover and look at numbers. or for a quick look, look at the casting marks on the face of head. are they the same? (example camel back) the face is where you see the 3 holes. are the marks in the casting the same? the marks will be more towards the combustion side. but on the face where the 3 bolt holes are. trying not to confuse you here.

 

If they are older heads which didn't come with accessory bolt holes, a previous owner may have drilled the holes but only on the front side. All heads after roughly 1969 come with accessory bolt holes. Since the heads are symmetrical, there should be holes on both ends.

 

The front of the pass head becomes the rear driver side and the front driverside becomes the pass rear when you swap the heads side to side.

the intake will need modded to fit those older school lower performance heads.

 

I looked at the heads today. It's hard to read the casting numbers on the heads. I got 3888338 and a D N on both, but one has GM 1 and H 26 while the other has GM 3 and H 24. Right now on the pass side of the engine there is one hole on the front and 3 in the back. On the drivers side there are 3 in the front and 1 in the back, which is how I believe both should be..?

 

I think you should yank off those antique heads and put on something more modern. Best info I can find on the casting numbers is that they are old truck heads with small intake runners and valves.

 

I know they are. Ha. Came with the engine.

 

Yeah, I cant find those heads anywhere. look again carefully. Sometimes the castings are tough to read. All I need is the last 3 numbers really. If you want you can google chevy head cast numbers and do the investigation. I always like tracking stuff down. But the number you gave, I can not find...

 

I went and took pictures so you can help me figure it out.

 

336X heads

 

I had the same thing go'n on with my '76 350, When I took my block and heads to the machine shop for re-work I also took the right serp. bracket. He mocked the head with one hole on the right then drilled-tapped the missing hole, this can be done while the engine is in the car but don't drill but about 3/4" deep.

He suggested lock tighting a stud in this one hole to assure all threads were being used.....

 

Thanks guys, ended up having to sell the engine. I put a lot of time and money into it, but I got $1,050 out of it and am getting a really clean '85 trans am now.