all i done was cleaned up the bowl area and gasket matched the heads,also i opened up the exhaust some,can i expect much as far as flow out of em?i am gonna stick a 1.74 exhaust valve in and have hardened seats istalled.any advice?im poor as hell(lol)so thats why i am doing all this work,haha

There great for building more compresion, they are good on a mild to warm 383, like my buddy has that runs low 12's. I couldn't give a set away.

516's can be made to work, but if you are not getting a 0.040" quench area, you may increase pre-ignition. Better off using a set of 452's as they already have 1.74 exhaust valves and hardened seats.

they are going on a stock 440,the pistons are down .120,im just trying to get some compression,the engine has a summit rv cam,think it was like .460ish lift and like 212@.050,the cam was a freebee,has a iron intake with a 750 holley and a set of headers.the ol truck went 9.41 in the 1/8.it's in a 68 sb truck,i have 2.76 gears and a 340 convertor

See if you can find some stock early 440 pistons and rods to swing in if you really want to up the compression, I just sold a set an hour ago.

With that cam you won't be losing much with those heads, sounds like a good combo other than the gears. Headers will do much more than any kind of head swap to a later set of heads.

I had a road test of a '65 426 Street Wedge car that ran 15s with the lo po cam, log manifolds, 516 heads, and small AFB. Headers, 3.91s, and a recurved distributor had it in the high 13s. Just step up the gear when you can.

i forgot too mention that the distributor has been recurved,im looking for a sure grip and then on too the gears,them dang suregrips are tough too come across reasonably priced,lol

What Rear do you have in the truck. I have a Dana 60 Suregrip that I will let go for cheap to you or anybody else.

8 3/4,but thank you sir