I need to make a decision with your input. Right now I have a '75 Duster 318 with A904(rebuilt with B&M shift kit and 3000 stall)and an 8 1/4 rebuilt rear with 3.55 SureGrip. Running approx. 300 hp plus 100 shot NOS good for 13.6 @ 102. Do you think the tranny and rearend will hold up with another 75 hp added? I only race for fun at the local strip, have factory A/C, ps and pb. Have also added frame connectors, XHD springs, and big block torsion bars. Took it on the Hot Rod Power Tour last year with no problems. I don't want to replace the tranny and rearend so would have no problem leaving things as they are, but you know how the need for speed hits you. So the survey would be to find out the prevalent opinion for adding more hp(via new heads) without having to replace tranny and rearend. Will they hold or not? Thanks.