Cliff's Quadrajet Parts and Rebuild Kits

The only thing i have found slowing the pump action is the, by ethanol, swollen black accpump cup provided in the lesser good kits.
The pump stem seal has never been an issue, used or new.
The older units did not use it, so not really necessary.

I have the OMC version of the same engine, same carb. According to them, the timing base timing was 6*BTDC if using 89 octane fuel (says it right on the flame arrestor) and 1* if using 87 octane. I have always used 89 or higher. These had a points distributor with mechanical advance (Prestolite, OMC and Merc used the same unit, just painted different colors) and at about 3200 rpm they would reach full advance which for the 4.3 was only 12* so 6*+12* advance = only 18* (+ or - 2*) total advance at 3200. I never found out why but the 4.3 is prone to detonation more than either the 5.0 or 5.7 V8s so they run much less spark advance.
My boat's a bit bigger (20'9") and a good deal heavier (approx 4200 lbs) I had to go with a 15x17 prop on the Cobra outdrive to get it to 4600, a 15.5x15 gave me approx 4900.
I actually weighed the boat on the trailer  and was shocked at how much it weighs. Full load is 5050 lbs and the trailer itself weighs 850. So the boat is a porky 4200 lbs!
If I repower it one day I know it should have a 5.7.

I have a 7042251 that came on a stock cast iron manifold. PM me an email addy and I can send you more pix.

Welcome to the Forum.

I see a few things that need to be addressed to get the carb where it needs to be.  When you are ready to start the build contact me at the shop.

I can put a custom kit together for it with HP and tuning parts so it's really close right off the bench....tks...

Thanks lightning boy, glad to be a member of this great forum community!