Originally Posted by NH2112
3) How about a cam swap to take advantage of the 4.0l head's better flow characteristics? I'm running stock cast pistons and can't tell you how much was removed from the head & deck, but the machinist said it'll still run on 87 octane. I've been told swapping to a. 4.0l head is a bolt-on 40hp and that with the right cam & jetting I'll see a nice increase in torque off idle as well, I might as well take advantage of it! If I can't get this thing right on the next try it's coming out and I'm swapping a diesel in like I should have done in the first place!
Well, a head's ability to flow air is only relevant if the cam gets the valve off its seat.
My gut tells me that a cam having roughly 260 degrees of advertised duration and cut on a 106 LSA (custom for sure) should pull like a freight truck in a 258.
Aside from that, you've moved beyond what a Weber 32/36 is capable of doing. I'd go to a 38 at a minimum or entertain a manifold swap and stepping up to a Holley 390 or even a 470 T/A.