You should EASILY be able to get into the mid 12s to 13 range with a 400, 428, or 455 without nitrous or power adders. I would recommend a 428 or 455. Depending on how much highway driving woudl determine the transmission. If you are going to do a lot of highway driving, put an overdrive in it, otherwise a TH400 with shift kit will do. As far as build up a MILD 428 or 455 would get you there, while a 400 would need to be only a little warmer with higher stall converter and steaper gear. I am more partial to the 455 (what's in my car), with ported and milled 6X-8 heads, Holley Street Dominator Intake, Holley 750 vacuum secondary carb, Lunati bracket Master II cam, 1.65 roller rockers, HEI ignition, Holley mechanical pump backed by a Holley red electric(not necessary), Block is milled .060" over and zero decked with TRW pistons. Compression is a pump gas friendly 9.2:1. It has 1 5/8 primary tube headers into a 3 inch collector into 2.5 inch pipe and 2.5 inch flowmasters. Also has the weld in subframe connectors as soon after I put the motor and tranny in it the body flexed enough to crack in the lower rear corner fo the driver quarter wondow. Rear leaf springs and sticky tires should easily put my 69 in the low to mid 11s. I'm afraid to put sticky tires on it though due to having the original 8.2 rear end in it. I'm still doing body work on the car, too, so it just sits still most of the time.
You're in Austin I see.....my old stomping ground. Grew up in Bastrop.
