I know that there is a 3.58 stroke crank for the 273-340. Found one with a 3.51 stroke. Need a special piston? a 3.58 piston work? THX

You should be able to use one intended for a 3.58 stroke it will just sit .040 farther down the bore. It will affect compression and quench but with a liuttle carefull calculating you could make it work just fine

I’m in the same boat with the same crank and I’m doing exactly that. Like HR Dave said. Using a 360 slug. It is possible to use a Chevy slug as well (3.48 stroke) with a call to the manufacturer for a pin size mod or generic rod use.
You could also ask for or search for valve reliefs @ 18* instead of the 23*.

Food for thought. (IMO, a 360 slug is just easier.)

You can ether mill the deck to meet the slug, or possibly find a long rod, use a low compression slug and super charge?

Remember it’s a 1050 crank, not a 4340, if it makes a difference to you.

Might try rod bloomer at bloomerperformance.com, great guy, I bought my stroker kit from him, he might have that stroke.

Thanks for all the input.

I have 9 sets of pistons from the old iroc series for 3.51 stroke small block. Some are Chevy rod some mopar. All around a 4" bore.

I have 9 sets of pistons from the old iroc series for 3.51 stroke small block. Some are Chevy rod some mopar. All around a 4" bore.

Doing a 318 build. Couldn't get a 4"" bore on this motor.

Now I wish you had said you were using an318 block to begin with!
That would have been some very good and pertinent information to disclose upfront.
Sonic check the block to see if it can go to a 4.00 bore. You may get lucky.

The 3.51 crank plus the 318 piston with four valve reliefs will get the piston just a little below or above a 9.600" deck. Those pistons typically have a compression height of 1.72".

If you need to leave the piston down farther in the block there are special low compression 318 pistons from the major manufacturers that have comp heights around 1.658.

R.