What is the tolerances people are using for a performance build these days.
I have a steel 455 crank and H beam eagle rods and a set of Valasco 4.260 BBO pistons that weigh 490 grams
what main and rod bearing clearance as well as ring gap and bore for a street strip build.

 

With 4.260 pistons the first thing I would do is sonic check the block. Then worry about clearances after that.

 

,134 over size Bore for these pistons is going to be close, thanks for the information.
I was wondering if the agle rods make any diffrence on machine specification -most olds engine builders recomend looser tolerance for rods and mains. From what i remeber.
mains-.0035 to .004
Rods -.003 to .0035

Not user about the eagle Rods though.

 

With Eagle rods and studded mains I shoot for .0027-.003 and .0032-.0035 respectively.

 

X2. I like those numbers for a street type build and a tad looser for race only stuff.