1fastxz

iTrader: (16)

going to build a N/A motor
using a standard LSX block
going with a 4.185 or 4.20 bore

should i go with a 4.0 stroke or a 4.10 stroke?

Going to be in a street car, mild cam
ported LS3 heads, fast intake 3500 stall auto

03supercobra

iTrader: (38)

I would definitely go with the 4.185 bore, just incase you needed to bore it out further in the future. Also on a NA application you would be fine running a 4.10 stroke.

1fastxz

iTrader: (16)

think im going to go with a 4.190 or 4.195 bore
the block needs to be honed

delphigto

iTrader: (4)

If you are going to spray it I would go 4.185 bore so you have more head gasket width between cylinders. I went with 4.185 bore and 4.125 stroke.

1fastxz

iTrader: (16)

its going to be a N/A motor

Eddie Krawiec

For a street car N/A 4.185 and if you are needing to buy a crank get atleast a 4.125. A larger crank will be free HP and give you a better tq curve. If I'm correct that should fit a 4.250 but at that point you start getting into some short rods and rod angles that put a lot of side load on the pistons.

Also if you did a 4.185 x 4.125 stroke the parts are easy with no wait time. Good luck with it.

03supercobra

iTrader: (38)

I believe on the standard deck, you can only use up to a 4.125 stroke.

If you go with a 4.125 stroke, make sure you have a good piston design, or it will burn oil.

1fastxz

iTrader: (16)

going with a 4.100 stroke
but will look into the piston design to