I had a similar sized cam in my +0.030" 426 and a tunnel ram with 11.6:1 compression, and it was between 585hp and 625hp with unported Indy heads. The head flow numbers will get you a better guess.

If DLI is still around, give them a call and find out right from them. The 800hp number I quoted was from a Barton SS motor single 4bl with 12.5:1 compression and a nasty cam not attainable without line boring the cam journals out. The heads they said had almost a full 40hrs of porting into them according to the article. Basically his SS heads on a milder motor for bracket racing.

Every point of compression is about 70-80hp on one of these motors.