I installed a small block in my 65 Tempest years ago. It had a six cylinder in it. No, the OHC six came along in '66. I found a '64 Chevelle in the bone yard (Victory, for those of you in Chicago). I got the brackets off of the frame. 'A' Body frames are all the same, so if you can find one of those you're in luck. I hear there are aftermarket brackets available, but I've never had to look for them. Yes, Chevelle headers fit just fine. I got lucky and found a set of Hooker Super Competition headers, never installed, at the Chevy/ Vette fest here for Fifty Bucks.