I've seen this issue discussed on several Chevy sites...and Ive seen it turn into cycber-nastiness from the vastly varied opinions.
Firstly, I know its cheaper to go buy a GM crate motor, than to assemble a 302. If I wanted a modern replacement with a warranty,
that's a direction to consider. I'm looking for a retro orange beast for the '46 truck. Perhaps a 3-duece nostalgia look ?
Secondly, I have an extra 283 laying around.
At first mention of a Chevy 302 to the common person on the street, you get the same reply...."NO, 302 IS A FORD MOTOR."
(The third reason I want a 302 CID, instead of a generic off-the-shelf 350)
I know Chevy made them for the Trans-am series, which was limited to 305 max. displacement...
I believe 68-69 Z28 had this option. The common direction to achieve 302 is de-stroking the 4.00 bore 327 with a 283 3.00 stroke crankshaft,
the other way is to bore a 283 from 3.875 to 4.000, for a total of 301.59 CID.
I've heard the arguments....that you cannot take a 283 to 1/8" over. I've I seen others say they did it for years, back when they could not afford a 327 block.
I know CERTAIN years of 283's CANNOT be taken that far out...but I've read the early blocks were thicker between the cylinders. (pre-63 maybe??)
Coming from building many old air-cooled motorcycle engines...I understand the heat issues that could develop, and the inevitable destruction that would follow.
Half the world says these early truck blocks were hardy, stolid creatures. The other half of the world says to stay away, and gain power from modern large cube blocks.
I've seen the small journal/large journal discussions...and the 4bolt main advantage discussions...
Anyway, the block I have is a #3849852 ('58-'61 Casting) Dated May '58. Which should be one of the blocks usable for punch-out.
The heads are junkie Triangle casting from '58. (1.72"/1.50" non-hardened seat, 59cc/9.25:1, no acces holes)
These, Ive read, are similar to the poochy 305 that Chevy built later...and will be tossed into the scrap pile.
Now to the crux of the biscuit:
I've located a source for 302 Z28 pistons...a tad on the expensive side...but, oh well. They are 11:1 comp, which
is too much for pump gas, yes? I'm going to go with big valve heads, but was wondering if I went to 70cc chambers over the 64cc,
if it would get me into the 10:1 range?
(I don't need to spin past 6500...I'm not looking for 500 HP with a blower.)
I want a nasty orange and aluminum Chevy motor, maybe in the 350/375HP range...
parked in front of a 700R4. Loud and bulletproof.
Anyone have first -hand experience with 302 displacement that could verify and/or add to this topic????
Suggest combinations??
Thanks in advance-
Luke
