My cam is really close to that, same 104 intake. I net the same exhaust lift with a 1.6 rocker.
This is what drives me nuts about my engine and why I've been trying to figure out where I went wrong with it. I have a decent-size cam and heads that flow almost 300 cfm. When I went to dyno it, I was sure it would make 525-530 hp. The torque is great but I'm convinced something is holding back the peak power.
It could use a bit more compression but I'm somewhat limited with iron head and pump premium. Using a Fel Pro .039" but am looking at a Cometic .027" which could give me a .3-.4 more squeeze.
On the dyno the smaller headers were probably a choke point but to what extent I'm not sure. I think the HV oil pump cost me a few HP so short of all that the one thing that really sticks in my mind as to what could be the limiting factor is the intake.
Maybe the 4" stroke needs a slightly longer runner? I really don't know. It's the easiest thing to replace so I do think it's worth a try. I'm taking the thing apart to check it so might as well.
I found one on Ebay for $300, will be here next week. Seller said it was gasket matched. Hopefully it works out OK.
