bmcnitt

Is there a good place that expains the exact differences between the 327's from 62 to 69. My biggest question is do they all have the same pistons? I know there are diff intakes, carbs/EFI, heads, ,etc,... for a 250, 300, 340,350??,365,375. I think they probably have some different cranks to right? I looked a little but didn't see a site that really laid it down component by component.

62Jeff

It's too big of a question.

Pistons had different shape for different compression ratios. Head's were different, in some cases the same head number had different valve sizes depending on application. Piston rods changed design through the years. Cams had different lift and duration depending on application. Some cams were for solid lifters, some hydraulic.

Just too big of a question, in my opinion.

MikeM

For all practical purposes, the '62-'67 327 parts would all interchange on those blocks. The '68 327 used a different block with larger main bearings. The crankshafts changed from steel to cast iron and had larger rod/main journals. The connecting rods were upsized for the larger journal. Also, the rear crankcase breather in the block disappeared with the '68 engine. Most anything else will interchange with the earlier engine even though not physically the same.

bmcnitt

Well with that being said you really answered my question, it sounds like there were a number of diff pistons which helps me with something I have been thinking about.

bmcnitt

Thanks, do you know of a list somewhere that has all the diff. components for a 68. Kind of trying to figure out what the weak link is in a 250hp 68. Probably everything, right? But if you changed intake, heads, exaust manifold could you see really big difference or would original cam, lifters, pistons be too much of a limitation. I know right off the bat people will say that is not the way you do a rebuild, I am just thinking of a few things and one is to approach a hp upgrade from a bolt-on only approach.

MikeM

If your engine is a '68, it should have flat top pistons in it. I believe there was a low compression, dished piston engine in '69. Maybe '68 too. Don't remember.

Why don't you get the engine code off the front pad on the block and post it. That would give an idea of what you really have. If you have the standard compression 327, you could add a cam/intake and pick up some horses. There's really no weak link in that engine for a street hop up.

Do a book search on "Chevrolet by the Numbers" by Alan Colvin. It'll tell you more than you want to know.