Joe Lucia,
Just wanted to thank you for the great advice you gave me related to how to determine which oil pump I had. I just finished the inspection you recommended in the attached posting and found that I indeed have the 3904826 for the L71. I'm slowly "finding all the parts" and this was a big find for me!!
Thanks again and take care,
BOB @ 36438
"COPY OF EARLIER POSTING"
Oil Pump C2 L71?
Bob @ 36438 -- Friday, 13 April 2007, at 9:23 p.m.
Can anyone identify the following:
Oil Pump number...(top half - bolts to the piece below which houses the impeller
with 5 larger size machine screws which have a "straight slot"):
3906829 with a "GM 20" Logo
Oil Pump Number...(bottom half - body where impeller is):
3904828 with a "GMT"
I've looked pretty closely and these appear to be the numbers - I'm very sure of the 3904828 #......
Re: Oil Pump C2 L71?
Joe Lucia -- Friday, 13 April 2007, at 9:48 p.m.
Bob------
There's no way to positively ID the pump assembly PART NUMBER from the casting numbers which you provided. However, the pump ASSEMBLY is very likely one of the following:
1) GM #3904826-----67-69 with special high performance big block, including L-71. Also SERVICE for 65-66 with SHP;
2) GM #3904827-----67-70 except SHP and HD.
It could also be other pumps, but the above are the most likely.
You could tell the above 2 pumps apart by doing the following: remove the oil pressure relief spring from the pump. Inspect the spring as follows:
24 coils, 2-7/16" free length, 5/16" OD, with light green stripe= GM #3904826
27/64" OD, 2-1/2" free length= GM #3904827
Just wanted to thank you for the great advice you gave me related to how to determine which oil pump I had. I just finished the inspection you recommended in the attached posting and found that I indeed have the 3904826 for the L71. I'm slowly "finding all the parts" and this was a big find for me!!
Thanks again and take care,
BOB @ 36438
"COPY OF EARLIER POSTING"
Oil Pump C2 L71?
Bob @ 36438 -- Friday, 13 April 2007, at 9:23 p.m.
Can anyone identify the following:
Oil Pump number...(top half - bolts to the piece below which houses the impeller
with 5 larger size machine screws which have a "straight slot"):
3906829 with a "GM 20" Logo
Oil Pump Number...(bottom half - body where impeller is):
3904828 with a "GMT"
I've looked pretty closely and these appear to be the numbers - I'm very sure of the 3904828 #......
Re: Oil Pump C2 L71?
Joe Lucia -- Friday, 13 April 2007, at 9:48 p.m.
Bob------
There's no way to positively ID the pump assembly PART NUMBER from the casting numbers which you provided. However, the pump ASSEMBLY is very likely one of the following:
1) GM #3904826-----67-69 with special high performance big block, including L-71. Also SERVICE for 65-66 with SHP;
2) GM #3904827-----67-70 except SHP and HD.
It could also be other pumps, but the above are the most likely.
You could tell the above 2 pumps apart by doing the following: remove the oil pressure relief spring from the pump. Inspect the spring as follows:
24 coils, 2-7/16" free length, 5/16" OD, with light green stripe= GM #3904826
27/64" OD, 2-1/2" free length= GM #3904827
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