I bought the performance bottom end rebuild kit from howell about 2 years ago and i am finally getting it installed. Here is the problem.... The kit is a standard bore not the 10 over or 20 over here in lies the problem. I was told by the mechanic that there may be a problem with the pistons and rings and not being able to use them due to a tapering of the cylinder walls from the stock pistons which is natural. Question is, should i be prepared to purchase new rings and pistons with the larger bore or is there hope that the standard bore will work? Has anyone heard of this problem before or has installed the standard bore kit with no problems?

If I need to get the new pistons... any suggestions on where to purchase them other than from howell (it took me about 9 months to receive a clutch)? looking for the JE pistons.

The car is a 97GS with about 110K on it.

you can order pistons from alot of places. modernperformance, direct je, maybe ert. but also maybe, look into getting another block from someone and try the stock bore pistons in the other one.

Originally posted by shibby97
The kit is a standard bore not the 10 over or 20 over
I was told by the mechanic that there may be a problem with the pistons and rings and not being able to use them due to a tapering of the cylinder walls from the stock pistons which is natural. Question is, should i be prepared to purchase new rings and pistons with the larger bore or is there hope that the standard bore will work?

Sounds like the mechanic was generalizing. I've never seen a stock 420a with any measurable wear on the pistons or cylinder walls. The only way to be sure if you need the block bored out is to inspect it for scratches, and mic each cylinder. In most cases, you'll only need a light hone job. Lots of us purchase .020 (20 over) pistons because we're just planning to bore them out anyways to be safe. If you bought standard size pistons, just have a machine shop inspect your block. Worst case is you'll have some wear, and have to sell the standard JE piston set on Ebay.

If you end up buying new ones, I recommend http://ajcustoms.com for JE pistons. $480 for a set of 4, including JE rings.

thanks for the info.

The best bet is to give your mechanic the spec sheet with the pistons and measure the skirts of the pistons and then the bores and see what the clearances are. If after that he thinks they won't fit with a hone there's a problem, or a need to bore depending on what the clearances look like.

Exile Racing Technologies
http://www.exileracing.com
Go that way, really fast, if something gets in your way... turn.

i went ahead and bought the .020 pistons. just thought it would be easier and bypass the possibility of the standard ones not being able to work. i'll be throwing a hahn stage 2 turbo on in the process so i figured it would be safer that way. so if anyone needs/knows someone that needs a set of standard JE pistons with rings just let me know.