72 340 AAWJ head questions

[aaron68s]

#1 are the stock valves a 1 groove lock stem?
#2 what is a safe amoumt to have them surfaced .020-.030? stock 72 pistons. thanks for any info. Aaron

 

[aaron68s]

the cam is .507 .510 lift

 

[moper]

#1 are the stock valves a 1 groove lock stem?
#2 what is a safe amoumt to have them surfaced .020-.030? stock 72 pistons. thanks for any info. Aaron

1> Nope. Intakes are 2 groove, exh is 4 grrove IIRC. You can buy performance aftermarket stock replacement locks for them tho
2> You can go further. But you end up creating issues that are more costly to adress - i.e. milling the intake flange side of the heads, sometimes intake itself, valve cover and intake fitment, and pushrod lengths.

 

[swinger340]

I have planed .060 off of some 587 72 340 heads. Planed the intake surface as well so an uncut intake would still bolt rite on. Cheap way to get a little more compression out of the engine w/o changing the stock (way in the hole) pistons. The compression was still only around 9.5:1 so I went with a .480 cam. Went pretty good when said and done. To compensate for the planed heads you can shim your rocker shafts, and/or run some adjustable rockers. I only went this route because it was a fresh short block. If I had built from scratch I would have bought some higher comp. pistons.

 

[aaron68s]

I have planed .060 off of some 587 72 340 heads. Planed the intake surface as well so an uncut intake would still bolt rite on. Cheap way to get a little more compression out of the engine w/o changing the stock (way in the hole) pistons. The compression was still only around 9.5:1 so I went with a .480 cam. Went pretty good when said and done. To compensate for the planed heads you can shim your rocker shafts, and/or run some adjustable rockers. I only went this route because it was a fresh short block. If I had built from scratch I would have bought some higher comp. pistons.

same thing here the short block is fresh and i dont wanna change the pistons.

 

[aaron68s]

1> Nope. Intakes are 2 groove, exh is 4 grrove IIRC. You can buy performance aftermarket stock replacement locks for them tho
2> You can go further. But you end up creating issues that are more costly to adress - i.e. milling the intake flange side of the heads, sometimes intake itself, valve cover and intake fitment, and pushrod lengths.

my comp spring kit has 626-16 locks says (These Chrysler four groove Steel Super Locks™ feature a 10° lock angle and 3/8" valve stem size. They are recommended for all race applications because Super Locks™ have a wider angle (10°) that better distributes the ever increasing valve spring loads over the retainer than typical 7° locks. Precision-machined out of super-tough, fatigue-resistant metal alloy, Super Locks™ fit any COMP Cams® 10° retainer) are these correct?

 

[swinger340]

same thing here the short block is fresh and i dont wanna change the pistons.

Have .060 taken off and run a short duration cam that is recommended for 9.5 or so to 1 compression and run her. With 1.88 valves and 3:55 gears my 4 speed swinger would run high 8s with this engine. Not an all out racer but a nice performing street engine. Sold it to a local. Is now in a 71 drop top cuda and he loves it. Or run some magnum heads and that will also boost your compression.

 

[aaron68s]

Have .060 taken off and run a short duration cam that is recommended for 9.5 or so to 1 compression and run her. With 1.88 valves and 3:55 gears my 4 speed swinger would run high 8s with this engine. Not an all out racer but a nice performing street engine. Sold it to a local. Is now in a 71 drop top cuda and he loves it. Or run some magnum heads and that will also boost your compression.

i do have a fresh set of magnums that already have 1.6 roller rockers setting on a shelf. that would save me the cost of machine work (150 bucks) I could go either way here. what do you guys think?