'72 LT-1 waterpump questions

[Tony 38901]

I'm replacing the waterpump in my LT-1 (330813) and am looking for a "temporary" pump while I send the original out for a rebuild. I have available to me GM Prformance Parts 14011012 aluminum unit for $122 locally and a cast iron unit for $152. I prefer to stick with GM products. I bought a $40 Bosch pump, but don't think I'll install that...even temporarily. Long term plans include a new motor to replace the LT-1, so I don't mind paying extra money for the GM pump. I also need to have my car on the road by this Friday, so I have no time for mailorder parts.
I think I'd prefer that over the cast iron unit. My question is, will the aluminum unit be a direct fit?

Thanks,
Tony

[Patrick H.]

Re: '72 LT-1 waterpump questions

I'd slap in the Bosch, or even a $25 parts store rebuild, if you only need a couple of weeks out of it until Art Gould gets yours back. Then again, I'd be leaving the LT-1 there too, but...

Patrick

[Joe L.]

Re: '72 LT-1 waterpump questions

Tony-----

I'm not sure if the 14011012 has a 5/8" or 3/4" pilot shaft. If it's 5/8", then you'll have to use a precision bushing to adapt it from 5/8" to 3/4" which your pullies require. Otherwise, it "should" bolt up and work just fine. I say "should" because, sometimes there can be little "quirks" with these aluminum pumps, GM or otherwise. One of the problems sometimes encounterd will be interference between the rear cover and the timing cover. Usually, for 71+ Corvettes, all that will be required IF this occurs is to change the rear cover bolts to button head bolts.

Another problem that can occur relates to fitment of the various brackets and braces that attach to the waterpump attaching bolts or studs. Aluminum pumps often have pump mounting bosses that are dimensionally different than stock pumps, so this can cause a problem in certain situations. For a 72 LT-1, you might find there is a fitment problem for the AIR pump support bracket or the adjusting brace. Spot facing of the waterpump mounting bosses or shimming, as required, will solve this problem.

Since I've never used a 14011012, I can't say that any of this will be a problem. However, keep in mind that these aluminum waterpumps, GM or otherwise, are, basically, a "generic" unit. They are intended to work for a wide array of applications which may have originally used slightly different stock pumps. So, there often have to be "compromises" in the design.