I have two sets of heads. Set #1 are 461's stock with 1.94 valves. Set #2 are 291's (Z28) with full port and polish and 2.02 valves. I am building two motors. #1 is a 327 with 097 mechanical SHP cam and popp-up pistons (stock) . #2 is a 355 with an L82 hydraulic HP cam and dished pistons. Both engines will use a stock alum intake with a carter AFB and factory 2" manifolds with under car exhaust. Which combination of engine and heads would be better. Car is used for cruises and sunday drives with only occasional bursts of whoopee. Thanks, Bob

 

How high are the pistons on the 327?

The 327 will be more fun. But if the pistons are too big you may have to run racing fuel.

The ported ones will be too big for the dished piston motor.

 

The 327 will be the equivalent of a L76, without the Holley. I plan to use regular head gaskets not the steel shim type to bring the comp ratio down below closer to 10.5:1. The engine and pistons were originally L79. Major difference is going mechanical. Carb and exhaust will be limiting factors but I hope the modified heads will partly offset them.

The 355 is an 8.5:1 should be good for regular gas and gobs of torque with the "weaker" heads but down on HP compared to the semi-hot 327.
Thanks for the input, Bob

 

Here are the specs on the L 82 cam:

3896962 Hyd. - 222/222 - .450/.460 - 114 - 350 L-46, L-82

I wish your 355 had closer to 9.1 compression... a set of Keith Black
Hyperetetic Flat tops are pretty cheap..

Here would be my wishes for you with what you have .... slightly
modified.
I like the duration on the L 82 cam.. but the heads you have really
need some lift to flow... they will only do 206 to 216 cfm at .500
so you really need to be as close to the .500 lift mark as possible to
hit your flow sweet spot.
I would run the 2.02's on the 355 and try to get compression up
with cheap flatop replacement.. or gaskets... or head shaving.. etc. to the 9.1 to 9.6:1 area.

I would run the L82 cam.. but with a twist... I would change the
rockers from the stock 1.5 ratio to 1.6, 1.65, or 1.7 ratio..

here is what the lift would be with those ratios on the L82 cam.

stock 1.5 ratio............... 450 int/460 ex lift
1.6 ratio ...................... 480 int/489 ex
1.65 ratio .................... 495 int/504 ex
1.7 ratio .................... 510 int/520 ex

to obtain lift changes with different rocker ratios.... divide the cam
lift by the stock 1.5.... then multiply that number by the new rocker
ratio... this will give you the corrected lift numbers.

If you go this direction make sure your springs are matched to the
new lift... Z28 springs are cheap and good to .480 lift I believe..
You can get 1.6 rockers in stamped steel just like the factory 1.5's
If you want to go higher in lift... I'd check with Summit or P.A.W or
one of the Dirt Track Claimer Motor Suppliers like Midwest Motorsports
or Smiley's and use thier house brand springs that handle 495 to 510 lift..

With L 82 duration, .480 to .510 lift, and 9.1 compression with those
heads on a 355... Im thinking you should be near 1hp per cubic inch..
maybe better if the port job was top flight... Good luck