Mild performance build of my original 327 for my 1964 Corvette

[bosco]

I have a nice 1964 Corvette roadster with a stout 383 stroker with old Trick Flow 23 degree heads. It makes about 425 HP and similar torque. I have the original 327/300 motor with 461 heads available. I would like to put the 327 back in with a few upgrades: Comp Cams 350 HP Nostalgia plus cam, L79 Aluminum intake, Bo Laws 650 or 750 Holley and maybe some mild porting on the heads. It has Hooker shorty headers into the sidepipes.


I want the original motor back in the car but without too much drop off in performance. Would the 327 at about 10.5 compression, and with the above mentioned upgrades approach 400 HP and say 375 torque?

The car looks near stock with the exception of 65 sidepipes, American 200 S Wheels. It does have Wilwood 4 wheel discs, and the F41 suspension. It handles and stops far better than original and I am not concerned about making it some 99 point show car, and will never sell it. Just kinda would like to say it has the original 327...BUT I NEED MORE SMOKE.

Thanks for you ideas and opinions

[Keith Morganstein]

I have a nice 1964 Corvette roadster with a stout 383 stroker with old Trick Flow 23 degree heads. It makes about 425 HP and similar torque. I have the original 327/300 motor with 461 heads available. I would like to put the 327 back in with a few upgrades: Comp Cams 350 HP Nostalgia plus cam, L79 Aluminum intake, Bo Laws 650 or 750 Holley and maybe some mild porting on the heads. It has Hooker shorty headers into the sidepipes.


I want the original motor back in the car but without too much drop off in performance. Would the 327 at about 10.5 compression, and with the above mentioned upgrades approach 400 HP and say 375 torque?

The car looks near stock with the exception of 65 sidepipes, American 200 S Wheels. It does have Wilwood 4 wheel discs, and the F41 suspension. It handles and stops far better than original and I am not concerned about making it some 99 point show car, and will never sell it. Just kinda would like to say it has the original 327...BUT I NEED MORE SMOKE.

Thanks for you ideas and opinions

It will run well, but not even close to the 383.

[Carnut1]

I love builds like this. I would not use the retro cam. Get Mike to grind a flat tappet. His little 206 @ .050" ft made 361 hp on a 306 Ford with modified E7TE heads David Vizard and I modified. A good tune up on the fuelies will get you 235-240 cfm and make nice power full on port job can go 260+. I actually like the l79 intake but years ago before a flowbench I did a bunch of airspeed work on one and to get airspeed at exits close it needed a notch in the center divider about an inch deep and an inch wide approximately. I have a pic somewhere. Airflow info from a real flowbench would be better. The l79 usually has horrible port alignment and could use a good match. Hei distributor will not fit. I would use the bigger carb. Thanks, Charlie

[bosco]

I love builds like this. I would not use the retro cam. Get Mike to grind a flat tappet. His little 206 @ .050" ft made 361 hp on a 306 Ford with modified E7TE heads David Vizard and I modified. A good tune up on the fuelies will get you 235-240 cfm and make nice power full on port job can go 260+. I actually like the l79 intake but years ago before a flowbench I did a bunch of airspeed work on one and to get airspeed at exits close it needed a notch in the center divider about an inch deep and an inch wide approximately. I have a pic somewhere. Airflow info from a real flowbench would be better. The l79 usually has horrible port alignment and could use a good match. Hei distributor will not fit. I would use the bigger carb. Thanks, Charlie

Good info, thanks

[Carnut1]

True a 383 and 331 are different and have a different feel. Yes the 331 will be down on torque but hp can be good. Rpm makes a difference, if you go ft stick to about 6500 rpm, I have done more on ft cams but that can be problematic. I remember the first time I opened up a stock 300hp 327 in my 65 SS impala with a power glide and sad stock gears. It only came to life after 3000 rpm. It had less low end than the 355's 383's I was building no doubt. I do think your estimated hp is high. Thanks, Charlie

[bosco]

True a 383 and 331 are different and have a different feel. Yes the 331 will be down on torque but hp can be good. Rpm makes a difference, if you go ft stick to about 6500 rpm, I have done more on ft cams but that can be problematic. I remember the first time I opened up a stock 300hp 327 in my 65 SS impala with a power glide and sad stock gears. It only came to life after 3000 rpm. It had less low end than the 355's 383's I was building no doubt. I do think your estimated hp is high. Thanks, Charlie

I think the 383 has a comp 280 H cam in it. Is that a bit too much for the 327 for the street.

[fdicrasto]

With your initial plan seems very close to the 340 hp 62-63 vette engines of that era. With 2.02 and 1.6 valves your near the 365 hp engine but down slightly in compression ratio. Totally agree that a mild flat tappet, similar to the 30-30 but less duration will surprise you but be very reliable.

[Carnut1]

From an old 331 thread Mike's choice. He is the cam expert. Gears, tranny, tires, weight, compression, carb, intended use all make a difference. I bet this is close to what he will recomend.

[rfoll]

A little face carving on an aftermarket aluminum head can make them look like ancient 461s. Paint them orange and throw some fine sand in the wet paint when you're done. Because it's a Corvette, It might not be a bad idea to find another block and crank and keep the original under the bench.

[Carnut1]

There is something nice about using the original block, heads and crank. I enjoy working up stock parts to make em run. I do have issues. Easy way just buy a 427 short block and plop on some 245 AFR's. I would hate that on an sweet old vette.

[bosco]

From an old 331 thread Mike's choice. He is the cam expert. Gears, tranny, tires, weight, compression, carb, intended use all make a difference. I bet this is close to what he will recomend.
[/quote

That cam sounds kinda small, doesn't it? The 350 Nostalgia is 312/308 (.468/462) and 229/236 at .050

[Carnut1]

From an old 331 thread Mike's choice. He is the cam expert. Gears, tranny, tires, weight, compression, carb, intended use all make a difference. I bet this is close to what he will recomend.
[/quote

That cam sounds kinda small, doesn't it? The 350 Nostalgia is 312/308 (.468/462) and 229/236 at .050

Have you calculated the compression? Too big a cam will turn a 331 to a real slug quick. How hard are you willing to twist it? As it is I would deck the block, mill the heads and run a thin metal head gasket to have a good quench number.

[Carnut1]

You didn't spec a piston so I figured a federal mogul forged flat top in my mind. Spec a pop up piston and spin balance the bottom gives you the freedom to use a bigger cam.

[PRH]

Imo, the difference in low speed grunt will be VERY noticeable, and along with that the perception about how “hot” the car is.

There is no way you won’t notice the loss of power........ and not by a little bit.

My suggestion would be to replace the top end of the 383 instead.
New TF double bump heads, stock intake, nostalgia cam.

Leave the 327 under the bench.

[bosco]

The factory compression was 10.25, supposedly. Likely more like 9.75. That Nostalgia plus cam is similar to their Extreme Energy cams and is a more modern take on the old 350 HP cam. What about going with a similar hydraulic roller? More expensive, but supposed to be more reliable.