I have a buddy who wants to build a mostly stock appearing small block for his A-body street driver. It's a mostly original 340 car and wants it to keep it's stock appearances and have about 425 HP, pump gas, hyd cam. He's not ultra cheap so no need to limit it to stock internals like rods, crank, etc. just trying to keep things under control as it's just going to be a cruiser/driver that he romps on occasionally. Car is a 4 speed, currently has 3.55 gears, and running stock 14 Rallye wheels with T/A radials.

Here are the parts available, any or none of them can be used, it's just what's on hand:

1971 360, J heads, complete torn down core in good shape, standard bore with lots of miles.

1971 340, J heads, complete torn down core in good shape, .020 over and will probably need a clean up.

1970 340, standard bore, ready for a bore job, bare block

1983 318, standard bore, complete, stock, good core, steel crank.

Lets here your build ideas!

What cid? Stroker is easy way to get there, and will work good with those gears.
Just the scat 9000 crank, scat rods, and KB hypers will do the trick.
Cam would be Comp's hi-lift cam, xe285hl. Do decent work to the heads, and an rpm intake with a 950HP on top and it should clear 425 by maybe another 25HP!
Brian

What's the definition of "mostly stock appearing?"
Aluminum heads or one of the sets of stockers listed?
Aluminum intake?
Headers or manifolds?
Agreed that stroking it is the easy way to get in the ballpark while keeping the outside stock. What you bolt to the block will determine how much HP/TQ you might get out of the combo.

I would think a 0 deck 340 -.030 over with worked j heads < mill heads with some stage one port work by someone who knowes j heads and a solid flat tappet with some good springs could net the power your looking for

He doesn't want to dump a bunch of money into iron heads, they would either be getting a mild pocket porting and a valve job or he'd just swap them for aluminum heads, the detraction from stock appearances on those being the sticking point but he'd live with it if they made the most sense (which they probably do). I told him to look out for some already finished/ported iron heads so he could possibly buy someone elses expensive work at a discount.

I'd build the 360 with 10.25:1, and a Crane 694561. The hedas will need a good 5 angle valve job, ad I'd do a gasket match and a bowl blending, set the chambers to 68ccs. Should make very close to 425hp with serious torque. I dont think it would cost more than $5K soup to nutz depensing on what he needs.

Ooops, dident see the 360 in the parts he listed, I would build the 360 too

I'd do a 360 with Edelbrocks, a good hydraulic cam, 950 with a Weiand X-Celerator or a RPM. My 340 with Ross flat tops, Hughes 236/242 @050, .592/.586 hydraulic, ported Edelbrocks, a 750 on an X-Celerator has gone 7.24 @ 95.04 on pump 93 in my 3300# 69 Dart.

A mostly street car with 3.55's?? I'd be looking at a 4" crank for sure.

Stroker crank is definately a consideration

As it turns out I have the motor scattered in bits and pieces in my garage. Should be no problem getting to 425hp with manifolds and a custom cam.

What motor Jeff?

Just some parts I have been collecting. 360 block, ported MP swirl port heads, KB pistons. stock crank or 4" (easier with a 4") weiand or ported stock intake.(cheaper and easier with the weiand), thermoquad.

here's what I'd do:

short block:

360 w/stock crank& rods (resized with ARP bolts), KB107's at 0 deck, new oil pump & balancer

heads: I'd probably bite the bullet, get some EQ318B's set up with 2.02/1.6 SBC +.1" valves, good 5 angle VJ, some bowl blending and open up the pushrod pinch some. this would yield 10.6:1 or so on the above short block

alternate: same valve job work done to whatever LA heads he has with 2.02 valves in them already, maybe shave them a few thou.

intake: eddie RPM w/ the edelbrock logo ground off

exhaust: headers

cam: I'd probably look at a comp XE274 or so if running mag 1.6 rockers. XE275HL if running 1.5 rockers.

even with the cost of the new heads, I don't see where it'd cost much more than $3500 to do something like this, and should be in the 420HP/440tq range easily....

Who makes an off the shelf .030 340 or 360 forged stroker piston for a 4.0 crank?

dish or flat top?

Keith Black, Diamond, Ross, JE, Wiseco all make shelf pistons in both styles for that app...

I'd use the 340, the 360 would work too, just a matter of what parts he can get deals on. Lots of cranks and other parts out there for sale right now.

340 .030 over 4" stroke = 416cid
360 .030 over 4" stroke = 408cid

figure 10:1
Air gap intake
750 holley
hydraulic cam in the neighborhood of .550 lift and 240@.050
I wouldn't use the old iron head


425 hp or just over 1 hp/cid is easy with todays parts. You probably could choke the motor off with the old iron heads and still make 425.

Why not go + .060 on the 360 = 414? piston cost is the same

Blastphomy! You said Holley!

It's getting a Thermoquad regardless!