Need 351 Cleveland HP suggestions

[Rolling Thunder]

To all Cleveland Engine Experts -

I could use some help. I am running a '72 351 CJ with open chamber 4V heads. The motor was profressionally rebuilt in 1987 and has approx. 18K miles on it. The rebuild included a .030 overbore, flat top pistons, balancing, and a 3 angle valve job. Heads were resurfaced, but I don't think they were milled, so compression should be in the 9.0 to 9.5:1 range (I think).

It has a Holley mech. sec. 700 DP with 70 primary jets and 78 secondaries. Intake is an Edelbrock Performer 351-4V dual plane. Hydrolic Cam has 290 total duration on both intake and exhaust with 220 on both at .050. Lift is .505, overlap 62 degrees. It does NOT have roller lifters nor rockers.

The previous (2nd) owner installed restrictor plates on the intake side, but the exhaust side plates are in the trunk of the car. Header tubes are either 1 7/8" or 2" diameter. Timing is set at 16 initial and 36 total.

After a recent tune-up, it was chassis dyno'd with results of 233 hp and 287 torque, but it was still running rather rich.

It seems there should be more streetable HP in this engine, even before swapping parts, I'm just not sure where, nor what mods have the best return for the dollar. Also, I keep getting conflicting suggestions - some say put the exhaust plates on, or better yet, switch to the Aussie heads. Others say pull the intake plates out and let it breathe. Still others say change the cam. Others suggest porting the heads, when yet others say they breathe too well for the street.

I would think these could rather easily be 400-450 HP motors, getting 300-350 to the rear wheels. Yet mine, with typical modifications, barely outperforms stock.

What suggestions do you have? What gains can I expect? What cost should I prepare for?

Thanks,

Keith