[screamingchief]

If you really wanna leave the shortblock "as-is" for now,here is how I'd approach this.

First thing first if you do opt to go the aftermarket head route,you'll for sure need to use the Kauffman D port heads and not the Edelbrock D port heads,and I'll explain why.

The E-D heads have the valve CL moved ever so slightly and that often poses a problem with "old school" pistons like you have with the valve reliefs in the "stock" location,now if you were using a more modern piston with the revised valve relief pockets,then you could use either head,but for now,the KRE D's are the best aftermarket head option with your current pistons.

Now that point is cleared up,the next order of business would be to choose the best head CC's,for your 400 cid combo.

That also affects the head gasket choices too in a way.

With the current piston situation you obviously have a few issues to try and deal with on this front.

So with the 74cc KRE D's and a standard head gasket and your poor deck clearance you'd be at like 9.2:1 or so (+/- like .25 CR),which for an aluminum head combo is pretty low no doubt.

A .027" thick cometic HG could bump that up like .25 point of CR to maybe 9.5:1 or so,but that's just mostly just amounts putting a band-aid on the real problem.

So my choice would be to opt for the 65cc KRE D's,along with using those .027" thick cometic head gaskets,as that combination of parts would both move the piston closer to the head for better overall quench (albeit down in the hole some) as well as reducing the chamber CC's to where the extra valve relief CC's become more or less a non-issue.

That would get you to like 10.30:1 CR,not @ all unheard of a CR for aluminum heads,matter of fact some would say that's an ideal CR for that sorta thing.

Then all you would need to do is pick out the porting level for those heads,here I'd likely just get the 260 cfm "entry level" ports for now,as that port level will still be a decent jump up from what you got now,and then later on they can be ported even further when you do end up going thru the shortblock.

Now I know what some are thinking,whats gonna happen when you rebuild later on and use some better pistons and maybe zero deck this thing,are'nt the 65cc chambers gonna be too small then?

Well they dont have to be,at least not so long as one is commited to keeping the stock 400 3.75" stroke that is,as the pistons I'd use for the next incarnation of this combo would be the #KB891 .040" over 14cc Icon dished forgings (which just so happens to be pretty close to the current valve relief cc's).

Then all you gotta do when you zero deck the next version is go back to using a .040" head gasket and the CR will be like 10.5:1.

And when you do eventually get around to doing the bottom end rebuild someday,I'd maybe bump the porting level up to the 290 cfm ports at that point as well.

So that's ^^^^ how I'd approach the whole aftermarket head option.

Next thing I'd wanna change would be the cam,for the time being I'd for sure opt for the Crower #60310 solid cam with some coolface lifters and not look back,the KRE D heads will already have good springs to run that sorta cam,so that part of the swap would be a no brainer to me.

And I'd swap that performer intake for a TII with that sorta combo seeing that it's using a Holley 750 cfm carb and such.

In the right car with proper tuning and decent traction,a combo like that should easily be a low 12 second combo,possibly even high 11's.

HP should be like 425 to 450 hp pretty easily.

And I'd leave the current gears & converter be for now too,they'll work just fine with this sorta combo.

JM2¢

Bret P.