496 build

I finally decided to go with a 4.250 stroke and build a 496 ci engine, i had my dad call comp. products(I never have time and they aren't open on weekends) and they said i'd have to have custom pistons made up for the 4.375 stroke and 6.535 rod, the tech suggested we use a 4.250(forged 4340) stroke and 6.800(h beam) rod, I don't know exactly what pistons he set us up with but the comp ratio came out to 10:1 with a 118cc head, the hole package came to $1,500 (whole rotating assembly rings bearings ect.) 781 heads should handle this with with 2.19 intake and 1.88exhaust valves, wanted to use roller cam (howards hydraulic roller lift .577/.579 duration @.050 222/234 lobe center 112) will the heads need to be machined for the cam (spring seats, guides) wanted to use a dual plane intake manifold or would it be better with a single plane, not going to rev it up very high, mostly be street driven, engine going in a 85 4x4 chevy truck 4 speed trans 4:10 gears, might get into truck pulling later on any input wouyld be great

thanks

that rod is longer than what i have in used any blocks i have built no i think it is not how i would do it but ? the piston will rock all over hi pin no skirt and put the pin in the oil rail on the street this holds oil in the pin and throws it on the walls more oil to deal with i think a 6.535 rod is all you need if your asking on the price PM me if you want to know want i really think. i deal with them all the time

I'll leave the piston/rods combo to Pat, that's his area of expertise. Sounds like a nice combo otherwise, I have used lots of Comp Products and Howards Cams, they're nice pieces, good quality, and they are nice to deal with. I would definitely go with a dual plane for what you're doing. Edelbrock Performer is prob. the most common choice. The Air Gap is nice, but it wont help with performance, it just looks cooler...and it will empty your wallet even more:CRY: The heads are a good choice. Check with your machinist, or Pat can comment on the machining. I think the spring pockets are OK, but you will prob. have to have the top of the valve guides machined down for that lift. Have good seals installed while they're at the shop, go with the larger valves, cc the chambers so you know where you're at, etc. Make sure you go with the springs that Howard's cams is recommending for that cam. You'll love it, it will be a torque monster for sure!:eek: John

I will agree with what Pat said 100%.
I would look at a SRP piston part #142980.
This is a shelf piston.
This piston will give you about 9 to 1 with your heads.
The piston is for a 6.385 rod.
The longest rod I would ever run in a street car with a 9.80 deck would be the 6.385.
If it where a 9.80 deck in a drag car well then I might look at the 6.535 rod.