I don't think TQs are known so much for cracking as warping so that they get vacuum leaks. I believe that as long as the "plastic" is good they have no other special problems. As far as an 800 carb on a 318, remember the purpose of the spread bore is to allow a larger carb size without having big primaries that drown the car around town. I personally think 550 for a big block is pretty small. I have a 625 on my 360 and it certainly isn't overcarbed, but for general cruising I guess you can't go wrong. Rob _________________________________________________________________ MSN 8 with e-mail virus protection service: 2 months FREE* http://join.msn.com/?page=features/virus