Brian, the 302 and 350 both share the same bore size (4.000") , and also the
journal diameters, but only in the later models of the 302. The 302 was
introduced by GM for the Trans Am racing series in 1967 and came with a
3.000" stroke (same as the 283 ci motor). It had the smaller 2.300" main
crank journals, and smaller 2.000" rod journals. These were beefed up in
68-69 to 2.450" and 2.100" respectively, so the whole line of 302s is not
even the same. I'm assuming this increase was due to bearing failures
during racing, and they had to change this and offer the same to the public
due to homologation rules. This same jpurnal change was made in the 327 at
this time.
On the other hand, the 350 main journals are 2.450" and the rod journals are
2.100", same as the 68-69 302s. However the stroke length of the 350 is
3.484", longer than that of the 302. This was achieved by lowering the
placement of the rod in the piston since the connecting rod lengths of both
motors are the same (5.703"). In fact GM kept doing this for every change
in stroke length until the 400 motor where they ran out of room. The rod
would have been too close to the piston crown so they shortened the rod
length in the 400.
I don't know about the head and intake matching situation.
Wally
> does anyone out there know exactally whats different between the chevy 302
> and 350? are the bores different sizes, or just the heads, or what? also,
> would a 350 intake bolt up to '67 302 heads? thanks for any help. its
> greatly appreciated.
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