I'm starting a engine rebuild for my 88 D150, figured I would sign up to pick some of your brains!

 

Welcome. Looks nice. What's your plans?

 

318 bored either 20 or 30 over. Stock Stroke. I'd like 400 at the crank.
My ideas:

360 cast iron heads
Hope fully I can reuse the factory connecting rods
KB399 pistons
9.5ish static compression ratio. Maybe higher, I usually run 91 octane, which is ethanol free up here. Not sure what the limit is for compression ratio and 91 octane.
904 torqueflite to save weight
Single Plane intake
engine was a factory roller cam, so I'll be using a roller cam, something like comp cams XR280HR-10 or XR286HR-10
I'd like for it to make power up to 6000-6500
3.90-4.10 in the 8.25 rear end

 

First, I'm not sure I'd expect 400 hp with that setup. 300, 330? sure, possibly. But who knows, the 318 is veeery underrated in my opinion. I think it was Hot Rod (or one of those) that did a 400 hp 318 build, and they had a lot of and work into that mill.

Second, I might do some research to make sure that 904 can handle the horse you are planning to throw at it. I'm not saying it can't, but I'd make sure because trucks and cars with any power normally came with the 727 for a reason.

 

Looks not too shabby but I do have some suggestions. For sure with that lift cut down the guides and check guide to retainer clearance. For sure look up SBM oil mods and do them.

Now this is how I would do it, open chamber heads have no quench, with that small dome and claying it might show tight enough clearance with maybe a deck cut but I'd use a flat top with aftermarket aluminum closed chamber heads, zero deck and .035"-.045" gasket.

Some measuring, porting on the cast 360 heads and a 750 cfm carb might get you there.

 

Welcome to the forum! Like your choice of the kb399 pistons, the stock rods are over 30 years old, I would go new. Sk mention the tranny, I agree, the 727 is aluminum housing and not that heavy. Planning on any racing? Think about a different rear end.

good luck,john