deuce4935

iTrader: (2)

I've got an oppurtunity to buy a bare ls1 block from a 2000 TA. The block has been recently cleaned, inspected, bored out to 3.905. My question is will a 6.125 rod work with this bore size on a stock crank?

fast01

iTrader: (16)

You'll need new pistons. The stock ones are 3.898", you can't use them in a 3.905" bore. Of course along with new pistons comes a balance job. The new slugs will be heavier.

deuce4935

iTrader: (2)

Will the stock rods still fit?

fast01

iTrader: (16)

Stock rods will work. The stockers are 6.098" (aftermarkets are 6.100"). In your first post you asked about 6.125" rods. Obviously, this rod length is only available in the aftermarket. You can use them, but you must get an aftermarket piston with the proper compression height. If you pick up the block you'll need aftermarket stuff anyway, so why not go with the longer rods too? The only negative I can think of going this route is that generally the machine shop will "fit" each piston to it's bore to optimize piston to wall clearance. Doing it this way you should measure each bore and piston with the proper mics and "fit" the pistons that way, trying to maintain proper clearance. Although, with modern CNC machining techniques, the variation in sizes should be minimal.