Don Terrill’s Speed-Talk

Considering a stroker added to a marine 350, making it a 383.

I have oem Vortec heads with 170 cc intake runners ( high rise Edelbrock intake)

This will also be with dished pistons . (18 or 22cc dish around 9ish C/R)- using pump gas

LT4 cam, 218 int./228 exh. with .492 lift w 1.5 rockers

Will this combination be rev limited by the intake runner volume or will it rev to 54-5500?

john

It will rev well past that, but it should make good power up to that point. I'd look into a valve job and some bowl work if you have the money, it can really pick up a lot when compared to the way they left the factory.

If you are going to order rods and pistions anyway go with a 6" rod instead of a 5.7. The engine with a limited head will run much better and the end cost is the same. I do quite a lot of them here using that same combo with great results.

the oem vortec head is limited to roughly .460-.480 lift without machine work if im not mistaken

A few years ago we built an 383 for a 55 chevy and used the 906 castings with just a good valve job and used a bowl hawg on the dyno it made 449 horse and 488 torque!!!

Can someone explain "bowl work".

Maybe some pics?

Thanks, John

( Yes, stock springs lift- .460/.480 noted)

ok , found an article from February 2009 -Popular Hot Rodding on bowl work (got sidetracked by Grace Potter music video! ooh la la)

Looks like some grinding work to remove sharp edges and such from factory work, and also smoothing of ports.

john