Thread: need help with 327

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I have a 1967 camaro with a 327 in it.. the casting number on the block is 3892657 is that a good?? Does anyone know what the compression ratio was on that block.. and what upgrades would i need to put a 142 blower on it?

thats a 2 bolt main block. Since it is Pre 1968 its small journal (rod and main journal is smaller then blocks manufactured after 68). HP is probly 250-280 i would say. (67 corvette 327's were 300hp), Compression would be 8.5 or 9.

Im not familiar with a 142 blower but a blower is a blower so you would need a 750cfm carb (most ppl run them on 142's and small blocks im told), headers, cam pretty lumpy if u are going supercharger, intake (get one to match cams's rpm range), raised compression (10.3 is nice to run on pump premium but u can run as high as 10.5 on pump premium), consider some heads (dart, vortec, 202 turbos, etc.), i dont know about a small main journal crank if they even make them :S, pushrods, valve springs to go with cam, ignition system maybe, the sky is the limit. but i would do all those before doing a blower.

if i were u i would take out the small journal block and either put a large journal 327 in its place, or a 357 (350 bored .040 over), or a stroker (383 (350 with a 400 crank bored .030 over) )

maybe consider doing a big block.

That should be a 10 to 1 or better motor. Unless you are making lots of power, the small journal, 2-bolt engines were very tough. I beat the hell out of them on the street, and the only one I ever broke, ran out of oil. (2 rods through the block and pan) Chevy used this combo for up to 375 HP for years.

Check the number stamped on the top of the block in front of the passenger head. The letters at the end of the number will tell the story.

If this is an original engine I would check a Chiltons manual for the compression ratio. Am I wrong or does not a blower cram more fuel and air into the engine than naturally aspirated and so I would expect you would want a LOWER compression ratio with the blower. If it starts out at 10:1 and you add a blower I would think even premium fuel would knock and you might need aviation fuel? I would guess you would want a CR around 8:1 with the blower???

Don Shillady
REtired Scientist/teen rodder