99VetteFRC

So lets ee if I have tis right! A 4.8 and a 5.3 are the same block. So the crank must have a different stroke. The 5.7 and the 5.3 have the same crank so the bore is different. So if I take the the stroker crank that is used to make LS1 383 inches in the 4.8 block and bore it out I should be able to get 383 or close to it out of my extra 4.8 block. Please correct me if I'm wrong as I don't know this for sure, I am just using a little deductive reasoning.

Bullitt4110

iTrader: (31)

Yes you are right, have your block bored to 3.905" and use a 4" crank, and you'll have a iron LS1 383.

Che70velle

iTrader: (6)

The 5.3, 5.7, 6.0, and 6.2's share the same crankshafts, DIMENSIONALLY speaking. The 4.8 has a unique stroke, as does the 7.0. GM basically uses multiple bore sizing to achieve different numbers...

99VetteFRC

I was on the right track then. I will start saving and scrounging forged stroker parts for my 4.8 block. Thanks for the confirmation guys!!!

Black98s10

But how far can you bore the 4.8/5.3 blocks and still have a reliable street motor? Would making it a 383 be okay for FI, or would the walls be to thin?

99VetteFRC

I do know the iron blocks can get bored way over the aluminum blocks. Just how much I don't know.

Bullitt4110

iTrader: (31)

A lot of people have gone to 3.905" without issue, the benefit of the iron block is you arent dealing with the sleeves like in the aluminum blocks.

the_merv

iTrader: (88)

Some people have taken 5.3 blocks out to 4.000 bore.. I guess a few can be machined that far..kinda pushin it tho.. Lol

99VetteFRC

I was just thinking about what to do with my extra 4.8 block that has a bad piston....

Che70velle

iTrader: (6)

I was told by a builder that the 6.0 iron blocks can go out .090
I'd take that with a grain of salt. Call a local machine shop, see what they have to say.