NINETNINEVETT

What are the main differences between a 63 327/340 hp and a 64 327/365hp motor. I know the carbs are different carter vs holly. Where is the extra 25 hp coming from. Thanks Mike

ghostrider20

The Camshaft for one.

The 64/65 - 327/365 SHP uses the "30-30" camshaft.

Seaside63

Valves were bigger on the 365hp.

Ironcross

Both correct.

DZAUTO

As already mentioned by 2 others, the FUNDAMENTAL differences are valve sizes (340-360hp engines had 1.94/1.5 and 350-365-375hp engines had 2.02/1.6 valves) and cam (57-63 had the "097" and 64 365-375hp had the "30-30"). The 340 had an AFB, the 365 had a Holley.
Those 3 were just about all that was different.
A 340hp engine can be upgraded by having the heads opened up to accept 2.02/1.6 valves (any good machine shop can do this), plus, the combustion chamber wall near the intake valve needs to be slightly machined (this was done on all 2.02 heads at the factory to unshroud the intake valve and improve flow). And a 30-30 can be installed. These 2 upgrades can be done without any "visual" differences, but a change to a Holley on a 340hp engine would be noticed by those who are knowledgeable.

Oh ya, just in case you would like to up the torque a little, a 327 can be very easily upgraded to a 350, simply by dropping in a 350 crank (sorta). This requires having your machine shop turn down the main bearing journals of a 350 crank to the size of a 327 crank. Then you use 350 rods and pistons. Bore it .030 and you have a 355. Also, the flange between the rear main journal and the rear oil seal journal of the 350 crank needs to be reduced just a little to fit into the smaller groove of the 327 block/cap. I converted a couple of 327s to 350 and this is just tooooooooooooooooooo easy. Its just like making a 383 from a 350!

acowboy

dzauto.....that sounds like a pretty neat trick to do to a 250 hp motor too.....any thoughts about gains if everything else kept stock? ie...intake, carb, ect..???

DZAUTO

A 250hp/327 used a small WCFB. That is somewhat of a limiting factor if you do all or any of the above mentioned upgrades. You COULD change the intake/carb to a 300hp setup (AFB) along with the other upgrades, but the knowledgeable folks would notice. The average Joe would not notice a 300hp manifold (cast iron similar to a 250hp manifold) and AFB. Also, you could search and search and search for a larger (cfm) WCFB that was used on the old 348 engines. They were just a touch larger than the WCFB on SB engines. (to do that kind of an upgrade to a 250 without OBVIOUS visual changes, I'd go with a 300hp AFB setup, bigger valves, bigger cam and install a 350 crank)

Also, when swapping in a 350 crank into a 327, I always use a 350 balancer (8in) and timing cover from a late 60s thru mid 70s 350. Again, ONLY those who are REAL knowledgeable are going to notice an 8in balancer instead of the 6in balancer on a 250hp-327.

bigcypress

dzauto i am truely impressed.

acowboy

thanks for the reply.....sure gives me something to think about over the winter!!

65convt

25 HP
I just had to

NINETNINEVETT

If you did the following that you suggest how much horsepower and torque would then have If you changed the manifold to the correct 365 + the correct holley. Thanks Mike

Oh ya, just in case you would like to up the torque a little, a 327 can be very easily upgraded to a 350, simply by dropping in a 350 crank (sorta). This requires having your machine shop turn down the main bearing journals of a 350 crank to the size of a 327 crank. Then you use 350 rods and pistons. Bore it .030 and you have a 355. Also, the flange between the rear main journal and the rear oil seal journal of the 350 crank needs to be reduced just a little to fit into the smaller groove of the 327 block/cap. I converted a couple of 327s to 350 and this is just tooooooooooooooooooo easy. Its just like making a 383 from a 350!