If you had both B and RB to choose from for blocks, which one would you prefer for this cid?

I don't think it matters. The 400 block is probably a little bit stronger but it is easier to find headers for the RB block. So it just depends on the car and what you're doing with it.

Shows that if you can live with the lumpier idle, the tighter lsa(TF cam is 108lsa) helps punch up the mid-range power.

Intake manifold ootb or tweaked a little?

What did you do for a baffle for the PCV valve?

Hp/ci almost identical to your 496.

Thanks for posting this Andy! I've been planning to build an engine like this for a while now. Did the customer build his own top end kit? I don't see a low deck kit from TF.

For the fun of it I built the same kit with a low deck intake on the Summit site using all of the parts listed in the RB kit and the price came out almost the same. $3955 vs $3925 for the kit. When I swap out the 240 heads for the 270 heads the price increases about $500 to $4566. Assuming I can get a solid roller cam for about the same price as the hydraulic one in the kit and port the intake to fit the 270 heads, would I see about 80-120 horsepower improvement over Trick Flows kit?

Both. If you are shooting for 750 hp then skip the TF intake and go straight to an Indy 400-2 or 400-3. You'll most likely also need to get the Indy intake ported to hit the 750 mark with a pump gas 512.

Thanks! When you say the TF intake is too small. Do you mean too small to make 750hp or to small for the 270 heads? I thought there was enough material to port the intake to the size of the intake ports on the 270.