Charly9g

Hi All. Just tore down my '71 455" Olds. Crank is worn, is it normal to clean it up .0010" ? Thought I'd go 40 over on the bore.Or can I safely go 60 over? Any suggestions? What r the best pistons? This is not a race car, just want a nice cruiser. (Cam?). By the way, this is in a 1957 Super 88! Want to stick w/a 4 barrel. Many Thanks, Charly9g

joe_padavano

I assume you mean 0.010" on the crank, which is common. If you can get 0.040 pistons, the less overbore the better, since that leaves metal for a future rebuild, but a 455 can safely go 0.060 over (and usually more) and 0.060 pistons are readily available.

chadman

Since you are just building a cruiser I would bore it over the least you can. If it's stock bore now I would just go +.030 and use Icon KB886 or KB887 pistons depending on where you want your compression to be. For the cam I would shoot for something with 215-220 @.050 intake duration and around .500 lift.

cutlassefi

X2 except I'd maybe go a little bigger on the cam if you're around 9.5:1 or better, maybe low to mid 220's and spread it a bit.

Jmo.

citcapp

That your installing the rebuild in a 57 caught my eye. I installed a 455 in my 57 Super 88 with a .040 overbore because of a really good buy on the KB pistons. If buying new I would stick with a .030 as stated above. X2 on the bigger cam

75cutty455

Is everyone on here suggsting the .030 overbore simply for room for the "next rebuild" or is there any other factor? Also, how much more of an increase of hp and or tq would one get from going .030 .040 .060 over bore?

firefrost gold

very little hp with a smal over bore it is the other tricks like cam , porting and head work that will net larger gains . A stroker set up would give a power upgrade also the less you bore the stronger the walls will be the better they will cool and less chance to change shape under load . Bill Travato Says you can never have to much stroke .