Okay... so I'm rebuilding an older dirt late model to run at my local half mile. Right now I have a SBM 383 that had some damage and I'm repairing it to run next season.

The original configuration of this motor was mostly Mopar.... 3.79 crank, 340 bushed rods, W-2 ported heads and an M-1 port matched intake, purple shaft solid flat tappet, Mopar adj. rockers (also came with a set of T&D's), 3/8" valves... you get the idea. The PO ran it no more than 6500-6700 RPM's. Dyno'd at 575 HP. The engine was run in an IMCA type modified.

Now that I'll be running with a faster crowd that 575 is a little on the lean side for HP. The guys are running up to a bit north of 750 HP and I see 8200 RPM's on some tachs. No place for heavy valves, stock rockers and such. Typically these are built by Clement, RCR, Yates or another big name shop. 30k engines are not uncommon.

So I'm thinking about building a 700 HP Gen 3 for 2019. There are several different routes to go with this... 362 spec engine, iron block/aluminum head combo @ 370 CI, IMCA mod engine (which I have... all iron, flat tappet cam), and an open class for unlimited cubes, all aluminum running a 15/16" restrictor plate. Gotta run a 4 barrel carb. I think I can get away with the stock crank trigger ignition with the MSD box set-up.

I think a cam change in my present combo could get me to 625-640 HP so I'll need a bit more to make it worth my trouble.

What I THINK I know...

Any 5.7 block should work.

Ported early heads can flow 300+ on the intake but the stock Apache's can beat that out of the box.

Stock PM rods won't make the cut.

Stock 5.7 crank is cast?

The oiling system is camshaft priority... that scares me in an endurance deal. Anyone mod the block to oil the crank first?

I'll need a solid roller... T&D and Jesel make rockers.

What I DON'T THINK I know...

Stock valve covers? Yes or no?

Stock cam tunnel is how big? Are roller bearings worth the cost?

How long are the stock valves? How big can the valve spring diameter be if the heads are cut? What's the max. lift the beehives can handle?

Mopar or Ritter intake?

Maximum bore size?

Half fill in the block needed?

I'll need 13 1/2 to 14-1 compression with methanol... any problems there?

This is a good start... I'll be back.

Last edited by Medlock51; 05/14/17 11:05 PM.