rod length for 3.78 stroke crank

70b7duster said
parts breakdown so far

-SCAT billet 3.79 stroke crank turned down to 2.100 journal size (use to race midgets/sprint cars, left over part)

-mopar aluminum comando heads w/ w2 intake and exhaust ports cut for 2.08 1.60 valves

-w2 m1 intake ported to the heads

-r3 block 9.6 deck

-mopar 50mm ugl cam

the part im debating on is, a freind is offering me a set of olliver chevy 6.125 rods which mean to run them the deck would need a considerable amount of material removed. OR do i buy longer rods and save the machining costs. SCAT has a 6.200 rod in the 2.100 journal size for around $500 with the arp 2000 7/16 bolt upgrade.

anyone have similar builds they can share their specs on?

Presumably, the R block can take a pretty big shave but I would think perhaps you start to sacrifice some strength at the top of the bore if you cut too much. How much do you figure you would have to cut?

I'll bet you could get some Chivvy pistons to work depending on your bore size or get a custom set made to fit the combo.

Also, that crank is still going to rev pretty high, especially with those heads and a stout block like an R block. That's potentially an 8,000 rpm combo with the right cam.

Here's a pretty in-depth discussion on rod length. Click me.