I have 2 bolts,both with 350s.The 72 came with a 350,the 55 has a transplant.Cant figure out what you guys have against 350s.Great running motors,stock or beefed up.Horsepower from around 160 to? the skies the limit.I have thought about putting a big block in the 72,but the cost is a little too high. The reason most of us stick with the 350 is cost and availability of parts.