Are all big block intermediate oil pump shafts the same length? I need a new bronze unit for a roller cam and I know when we first got this motor ready to fire last winter I had one that was too long but can't remember why??

I have a 400 low deck block, Melling oil pump with an Indy cover on it. Single line external oiling.

nope. there are three that i know of- maybe four, depending on if it's low deck, rb, milodon pump, etc.

the longer unit is for the race unit that feeds the pump from both ends. it has like an extra plate sandwiched between the pump & the block.

The stockers are the same length. There is some different lengths for the hex part due to the depth of some of the racing pumps, but if you are using a stock type pump use any of the big block shafts...unless you have a roller cam.

In your case, you will need the bronze gear for the roller, and you will need the extended hex drive for the deeper pump.

there is also an extra long one for the Keith Black double pumps.

The Barton billet alum. pump is longer also.

Thanks guys, I just took mine out tonite to measure it, should have just done that in the first place. Funny thing is I didn't even measure it as I expected it to be worn badly and in need of replacement but it is fine.

if you're not using anything between the melling pump and block you need a stock length shaft which is the shortest one. iirc of the three "common" lengths the stock pump uses the shortest, the milodon external feed pump uses the next longest and using a stock type pump with the milodon external feed spacer uses the longest one.

Three different lengths, all available in either bronze or steel. Total of 6 different part numbers. This info is in my book.