1965-66 Big Block Oil Pump

[Joe L.]

As a follow-up to another thread I started, if anyone out there has a known original 1965-66 oil pump, especially one removed from a 1966 L-36, I'd be very interested in having you open it up, measure the gear length, and photograph the pump body and cover.

[Patrick B.]

Re: 1965-66 Big Block Oil Pump

Joe: I posted some pictures of the 1.3" pump I think came out of my 69 ZL-1 engine on your previous thread. The casting numbers were hard to read. Could you read them and did they correspond to a pump you knew about?

[Joe L.]

Re: 1965-66 Big Block Oil Pump

Joe: I posted some pictures of the 1.3" pump I think came out of my 69 ZL-1 engine on your previous thread. The casting numbers were hard to read. Could you read them and did they correspond to a pump you knew about?

Patrick------


Yes, I saw those. However, I was not really able to discern them, either. Nevertheless, I'm virtually certain the second digit is a "9", as I would expect. The following digits I could not see clearly enough to say what they are. I certainly wish I could determine what they are with certainty.

It's very clear, though, that this pump body casting number is not the same as that used for 1965-66. So, that leaves unanswered the question of why they needed to create a new casting for a 1.30" gear big block pump casting for the 1969 ZL-1 when they apparently already had such a casting as utilized for 1965-66.

[Bill W.]

Re: 1965-66 Big Block Oil Pump

If you still need a photo I have an org 65 BB pump. Its dirty let me know. I dont know how to post photos but I can e mail them....Bill

[Joe L.]

Re: 1965-66 Big Block Oil Pump

If you still need a photo I have an org 65 BB pump. Its dirty let me know. I dont know how to post photos but I can e mail them....Bill

Bill-----


Thanks. I'll send you my email address. Also, is it possible for you to open it up and measure the gear length? It's very simple and easy to do this. Just remove the 5 cover screws, remove the cover, and pull out one of the gears.

If I can get someone to do the same with a 1966 L-36 pump, I think I'll have the whole picture.

[Ronald L.]

Re: 1965-66 Big Block Oil Pump

Joe, you should have asked two years ago when I posted pics of a pick-up that matches that of Mark's and some thought it to be a non original pickup/pump

Now that the leaking pan gasket is fixed...it will be a long time before that pan comes off. I don't think I took any photos that would tell us anything, I looked through earlier this year.

[Bill W.]

Re: 1965-66 Big Block Oil Pump

Joe I just opened my 65 pump . It had a large green stripe of paint on the outside . The gears measured about 1 3/8" they wont come out . It has two casting #s
the top one is 3880376 /GM1. the lower is 3880370 /GM
this pump came out of 396 # 16120. The engine came out of the car around 1967. What do I have ? ps the pick up tube was a press fit in the pump. Bill

[Michael H.]

Re: 1965-66 Big Block Oil Pump

Joe I just opened my 65 pump . It had a large green stripe of paint on the outside . The gears measured about 1 3/8" they wont come out . It has two casting #s
the top one is 3880376 /GM1. the lower is 3880370 /GM
this pump came out of 396 # 16120. The engine came out of the car around 1967. What do I have ? ps the pick up tube was a press fit in the pump. Bill

Bill,

That sounds like a casting number from somewhere around the intro of the 66 model.

[Joe L.]

Re: 1965-66 Big Block Oil Pump

Joe I just opened my 65 pump . It had a large green stripe of paint on the outside . The gears measured about 1 3/8" they wont come out . It has two casting #s
the top one is 3880376 /GM1. the lower is 3880370 /GM
this pump came out of 396 # 16120. The engine came out of the car around 1967. What do I have ? ps the pick up tube was a press fit in the pump. Bill

Bill------


I believe the numbers are actually 3860376 and 3860370. Those were the numbers I found on the other 65-66 pump I "autopsied".

This sounds like the 65-66 pump which is just what it should be coming from a 1965 L-78. I'm surprised the gears would not come out easily. Is there significant corrosion? In any event, it sounds like the gears are 1.30" which is what I found in the other 65-66 pump (of unknown exact origin) I opened up. It also had a green dye mark on the outside of the body.