I would like to get more compression out of my 460.Putting 429 pistons (standard) should do it.?What else must be changed?And are there any block huggers for a 78 460.If not how much cutting will need to be done with standard headers like Dynomax? Thank you all!
I dont really know 385 series engines, but I'd try putting on the 71 or earlier heads from a 460 before i put 429 pistons in it, they had smaller combustions chambers and are more likely to fit in the block than 429 pistons, but again, I dont know the differences between 429 and 460 psitons, it's a matter of compression height more than bore size or anything
You need to stick with a 460 piston and rod...if you use a 429 piston the piston will actually have the head sticking out of the block with the longer stroke of the 460 crank. Anything above 9.5 to 1 compression will be on the verge of detonation with todays gas. You might be able to run 10 or 10.5 to one compression but will have to retard the timing which in effect will lose the horsepower you were trying to gain.
The 429 and 460 use the same rods so the piston is made differently to deal with the extra stroke on the 460 so it's not a good idea to use them. If you don't want to go through the expense and trouble of getting the early style heads, just get yours milled. Milling will decrease the combustion chamber size, as well as helping to unshroud the valve, a big power improver. Check with the machinist to see what is a safe cut and how much compression you'll pick up, I think a full point gain is possible.
Just to add my own opinion, get a set of older closed chamber 460 or 429 heads. Only difference between a 429 and a 460 is the crank and the pin height on the piston. That's it. Everything else is the same. Getting an older set of heads (i.e. part # DOVE-C) That would up the compression to about 10 - 10.5:1 and would yeild a signifacant increase in horsepower. You could still run on pump gas, would have to be premium but it would run fine. A friend of mine has a 1974 F-250 4x4 with a BUILT 460. He's pushing at least 10.7:1 compression with older style heads and he just runs premium gas, never spark knocks, plugs are always proof of it burning totally. That's the best and easiest way to gain what you want if you ask me.