My 68 Firebird resto is coming along nicely and I am going to build an engine for her this winter, and I am wondering if anyone has an idea what would be a realistic max torque/HP would be before twisting the poor old frame...and no I won't be using drag slicks, just street tires, so maybe I just answered my own question...I'll just buy more tires... I think the max HP was 335 in 1968, according to the books. My plan is to build a 455, not crazy HP but maybe 400HP, 500 ft/lbs ...is that reasonable in a convertible?

Thanks

Probably fine. That's not much more than the stock issue that came in some of these cars originally.

My build in my ‘68 ‘vert is conservatively 500hp. As long as you’re wearing street tires, you have no worries...except the expense of the tires...LOL

Okay thx guys. I'm still trying to decide engine to use. The 455 will be the torque monster, the 350 will be no problem.

Cheers

Cracked windshields(body flex) on both my 67(400 M/T 3.36grs) and 68(455 TH400 3.42s)
Even cracked left upper a piller on 68.
Highly recommend at least bolt on frame connecters.