Mike, asking me about engine building will just be repeating what I have learned on this site for the most part. Mr. P who answered on this posting is the expert here. He has also, as stated before, written some of Jim Hands book. I have done nothing special to my heads or 400's as of yet. That said, I did turn a couple of mid 14's in the upper 90's in my 76 T/A this past fall.
What you must know about this engine is that the whole thing cost me $200. It came out of a Public Storage auctioned unit. My original stock 400 in the T/A was bad, so Dad and I installed this one. We could tell it was .030 with forged pistons and Comps Extreme Energy 268H cam with stock converter in a T350 with 2.41 rear gears.
I am now building a 428, with Mr. P, Geno's, and others help from this site. It will be a .035 over with Chevy Eagle H-Beam 4340 6.8 rods, Ross Pistons, solid roller cam with a Torker II intake and AED 850 Holley. Probably start with my #13 heads and then eventually upgrade to a nice set of E heads. I am using the stock crank and 2 bolt mains with the Rod Journals turned down for the 6.8 rods.
Also installing a pretty stout T400 with Continental 3500 stall, upgrading the rear end to a Detroit Locker, Moser Axels, Moser C Clip eliminators and Richmond 3.42:1 ring and pinion in a bigger 10 bolt 8.5 housing.
This will be a street/strip T/A and hoping to get in the lower 12's or high 11's. I don't want to roll-cage this car. I have a 64 Lemans that will become full time trailer race car that will get all that stuff.