Tried on performance forum, but I guess I am too slow!!!

I have my basic engine set up -
402 2 Bolt Block - will be bored .060
781 Oval Open Chamber heads - will be 2.19 1.88 Valves
Stock Cast Crank

Rest of planned build-
7/16 reman. or Eagle SIR Rods
Something lumpy from Lunati Harold?
RPM Air Gap
Holley HP
1.72 rollers

Questions -
What Pistons do I use for 10.5 compression?

Do I need to deck the block to raise the piston in the hole?

What valvesprings would be best?

Approriate Header size?

Don't wanna beat the world - just wanna be able to cruise to the track - lay down some nice numbers (12s?), and cruise home...

Joe

Speed Pro makes several pistons for a 402 but my catolog only shows Closed Chamber Heads. What is the cc's of your head?

336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports


Thanks,

Joe

you could run the 375 hp 396 trw forged units they are the factory replacement pistons. in fact i have a set of them in my garage for a 4.155 bore 396 which would be .060 over 396 or .030 over 402. with your heads and running a steel shimmed head gasket should get ya what your looking for in the compression area. they have like a .500 some dome and they are for the closed chambered heads which are fine for open chambered heads. i know they gave me 11.7 to 1 compression with a 100 cc head and .039 gasket. so your 18 cc bigger then me and thats about a 1.8 reduction in compression so that would be about 9.9 for you then go shimmed gasket and gain .5 so it would give ya about 10.4 .....lol dont you just love my math .....

i would not worry about decking the block i would just clean it up and true it with the min amount removed then just used a steel shimmed head gasket. ive been running some really good name brand pistons(trw and keith black) and im sure glade i dont take much off cause all these pistons in my blocks have been running right at .015 in the hole and then i run steel shimmed and thats cutting it close of the clearence for the piston to smack the head.

as far a valve springs it just depends on the cam which one to run.

as far as headers go i can only tell you from my own experience. i have ran the summit headers for 79 bucks for well over 13 years ive owned two sets so far but they have been on a dozen engine combos over the years. and they work very well into the 10's now i have tried the 2" primary headers when my car was running deep into the 12's turning 7000 rpms and i lost power all thru the rpm range and with 2" headers i lost 1 sec in the 1/4 back to the 13's and lost 8 mph and no crap this was with NO other changes. i bought the headers for 50 bucks used off a 468 bbc and bolted them on then went to the track over the weekend and was so ticked i put my old headers back on and my times was right back at the 12.20's mark at 110 mph

now i do have a combo for a very solid 11 sec ride that i drove on the street and got 11 mpg during 200 mile road trips.

but you might think its to much not sure.

i even still have the cam that got me there. on the shelf. if interest let me know and ill post everything.

yes , i would like to see your combo. You can email me if you would like.

Also if you would like to sell the pistons, email me...

Joe

Can I use stock 454 Piston, with a .125 overbore to make a 427?

Joe

You can't use a 454 piston in a 427 without going to a longer con rod. The pin height is higher in the 454 piston to compensate for the longer stroke of the 454. 427's and 454's used the same length rod.

What would compression be with these

Speed-Pro Powerforged Pistons (#844-L2328F60). Specs say same as L78/L89 375 hp. Dome height is .335". Compression is listed at 10.8:1 with 106.9cc heads

and these...

336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports

Joe