Does anyone know if '73 455 Heads will work on a '67 430 Engine. if so what mods are needed? Thanks, Doug
The heads will bolt on no problem using standard composition head gaskets. The main problem is confirming that they have the oiling passages at the front rocker tower for the though the head rocker oiling. Otherwise you will have to convert to the later through the pushrod oiling. Also you will need to block off all the AIR holes plus the exhaust crossover passages (because of the big opening in the center of the head) unless you use the '73 intake or appropriate later model Edelbrock intake with the full length sides. If you block off all the exhaust passages you could use the '67 intake with the early gasket and I think you wouldn't notice the big center exhaust crossover opening. You may have to drill out the '67 intake mounting holes to get the '73 bolts to fit, 3/8" vs. 7/16". I think they are the sizes. The biggest problem with blocking off all of the exhaust crossover is if you want to run the factory choke during the winter. Might take a while to pull off. Also could be a slight decrease in compression because of the possibly larger chambers of the 73's.
Also the 73 and later head have 2 water ports in the center on the gasket surface up towards the intake.......the 72 and earlier blocks only have 1 "scallop" in this location not 2.......you need to plug the hole that doesn't have the scallop or antifreeze will run into the pan very quickly
Met someone today with proform Buick shaft rockers. Looking to plug ends of shafts and use them and 455 pushrods and lifters on 69 430. I advised to plug off passageway on deck of block supplying oil to heads. Owner did not want to remove heads and mentioned high volume pump as solution.I mentioned plugging the oil port inside of rocker pedestals.
This makes second time I have heard of something like this, the first was someone capping off ends of 70's style ( cant remember) . What I do recall is viewing the ruined block 68 vintage.
You could drill the hole in the stands and tap and plug there without pulling heads.....have to take care with the metal chips
We, (the shop) will build 430 complete using 72 heads / pushrods/ rockers. The heads have egr ports at intake flange. I understand the 4 small holes have to be piugged at both ends where intake gasket would not seal. And the center crossover port as well?
For the last 10-15 years I've been running my 430 with the late model rockers. I filled the oil passage on the stand with RTV and bolted the shaft on. There is very little oil pressure there. Gotta figure the pushrods bleed it all off. I've had no issues.
There is 0 oil that comes up stk 430 pushrods...........they oiled through that hole, through the shaft, and down the pushrods. That hole when not plugged up with sludge and what not see full oil psi.
I think you missed my point. I know how the 430 rockers oil. After converting to the later rockers with thru pushrod oiling, there are 16 lifters/rockers bleeding pressure from the same source as those two oil feed lines. There's little pressure left at that point. A dab of rtv is all it takes. I surmise thats why buick left that passage open on the later blocks.
The passages are left open so earlier heads could be used and still work........on the later block the solid head seals against the headmaster. I'm glad this works for you, but I could never recommend that to someone else......I would prefer a more positive sealing... What i would do on my car knowing what the possible outcome risks are and accepting that.........I wouldn't recommend others to do several things I have safety gotten away with
