I use a 440 block with my 493 as I like the fact of the better intake manifold selection for the RB block. And mine is a pump gas street car that I knew I would only race a few times a year at the most so I was not worried that the 400 block has the stronger low end. I went with the basic Indy EZ heads as I felt they have more potential if I want to step it up some down the road and I like the fact that the exh ports are in stock location and you dont need offset rockers. I also use 440Source D-dished pistons to get pump gas friendly 10.6 comp and I built good quench in it. I use a custom cam from Dwayne Porter thats .585 and .592 lift with 264 & 270 @ .050 on a 110 LSA. I have it in the eng on a 106 ICL. I used the 440Source 4.15 stroker kit and run the Indy dual plane intake with an 850 DP carb. Its a street car that I love to drive and the cam gives it the idle I love and makes decent power with good driveability. At just over 3700 lbs its run 10.70's in street trim just like I drive it as I usually drive it to the track and race on 92 pump through the full exh system. At 3200 lbs you should be able to build a nice pump gas eng to get you the 10.20's you want. And honestly I have not really gotten after my car as with my bad knees and back I just dont take the time to go after the tune as I have been happy to just leave it as it is and drive and race it like that. If I dropped 500 lbs and set it up as a race car I feel I could hit 10.20's without much trouble. Good luck with yours. Ron