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Rebuilding 428 Ventura Engine


New member
I have a '67 Pontiac Ventura with a 428 engine. The rear main-seal is leaking. I plan on replacing the seal. The question is: Do I replace it through the oil pan/crank or split the tranny from the engine and remove the flywheel? Can anyone please help?


Staff member
i have heard of people doing it thru the oil pan but you would have to search for a write up of the specific steps involved. I believe it involves using a hooked tool sort of like a dental pick and rotating the crankshaft. If I find it I will post it here. Did some further research, if you want to do this only once, you got to pull the trani. Seems this is the hottest new seal technology
Last edited:


New member
HI,to replace the seal, you will have to remove oil pan drop, rear main cap, fish the rope seal out and install a new one. it takes a special tool to remove and install rope seal. There is a two piece seal out it is a viton seal they're about 40 bucks. its like a chevy seal, should be easier to install.you may be better off to pull engine to get oil pan off. you have to jack engine up so far on a pontiac to get it off. Good luck on your project.