Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, please

Update: Need some help with identification and verification

Well, took the block apart...

The "rebuilt" motor was in fact a 1968 block with a P0 casting number. Looks straight, and the cam slid out easily...

I left the oil pan on until after I pulled the intake, heads, and exhaust, and cam.
Well, the first quart that poured out was water, followed by about a cup of grey gloop, and then engine oil. ou:

I noticed on both of the heads that there were about 4 or 5 holes that did not match with the water jackets on the block.

Figured I had later model ('73-'80) heads slapped on a '68 block. If I remember what I just saw, there are 2 or 3 holes in the center of the head that don't match up with the block. The gaskets used covered up a couple of them, and there was rusty gook in the heads where the water jackets were blocked.

I checked the heads, and they are casting number 1243452.

From the Buick.god website, I determined that they were '70-'71 heads. Why don't water jackets match?

Are '71 heads OK on a '68 block? From all I have read on this board, '68-'72 heads should match '68-'72 blocks... But the water jackets don't match, and there are holes in the heads that will pour directly into the lifter valley if not for the head gasket... I don't think that they match...

On the "good news" front, the Crower Level I cam and lifters are in.

My next question: What is the correct size pushrod to use for a '68 block, and a '72 block? With the the current mishmash of heads and block, I don't know if I have the correct pushrods.

My course of action now is to determine if I've got any '68-'72 heads. If not, I will tear apart the 1972 350-2v motor and go from there. Probably use the pistons from the '68.

And a big thanks in advance for the help.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

So by the looks of the numbers on your heads you had late model heads on an early engine and only the gasket was keeping the coolant out of your crankcase. Only use 68-71 heads on the early blocks.

If your pistons are the same weight as stock then sure you can match them up for weight and then rebuild the engine however if the pistons are more or less in weight then you should really have the engine balanced internally.

Keep in mind that to balance an engine internally you need a neutral balanced flexplate and balancer.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Thanks, Sean.

I think the interchangeability of heads and blocks should be based on actually matching them up and looking to see if there are water jackets in the center of the head that go "inboard" of the block skirt in the lifter valley area.

The later blocks should have a center area built up to match. I cannot confirm right now, but the later blocks with the built up area DO NOT have water passages, but do act as a means to block the water.

Another thing to note: when I looked at the buickgod website again, there are no lines separating the casting numbers in relation to years, they are grouped...what looked like a straight read across to '70-'71 heads was actually a mistake. The 1243452 heads are the second in a list for '72-'80 heads (per the website).

I guess then lesson here is that '72 heads with a build up in the center and water jackets DO NOT match earlier blocks...

I guess the interchangeability would now be limited to '68-'71 heads, with the caveat that you have to check for a built up area in the block to match the later heads with the open water jackets in the center.