Identify this 40018 fuel pump?

[Verne_Frantz]

Could anyone provide me with the correct application(s) for this fuel pump? I know the 40018s are 3/8th line and used for some hi-perf engines. This one is beyond my area of understanding and I don't understand the prefix numbers in the stamping.
Thanks to anyone who can help.

Verne http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

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[Mr70]

All late assembled 1958 348cid. w/3-2bbl.carb.
1959-61 ALL w/348cid. w/F.I. used a 5/16" line.
1962 Chevrolet w/327cid. & 409cid. used a 5/16" line.
1963-65 Chevrolet & Corvette w/327cid.& F.I. used a 5/16" line.
Any 1966-Chevy II,Chevelle,Chevrolet or Corvette w/283cid. 4bbl. or 327cid. with either 275Hp,300Hp or 350Hp. all used a 3/8" line.

[Verne_Frantz]

Thanks Rick. I know that number is applied to those applications as a replacement, but I was wondering which factory installations would use one of this style. At least up through '64, all original pumps were the screw together type and not a sealed unit like this one. I was hoping the 325M prefix might be a clue.

Verne http://www.yenko.net/ubbthreads/images/graemlins/wink.gif

[Mr70]

No cover screws means it's a Unitac design,so no diaphragm or repair kits were available for it.325M is saying it's a late 1960's vintage replacement variation (1966 I believe) from the original cover screw design of the 1950's-early 1960's.