If you read my other recent thread about oil pressure problems, I have decided to go back to a stock pump. I called CarQuest today and my friend wanted to know if it had a 1 5/8 or 1 3/4 oil pump, both are standard pumps not high volume. Originally the engine had a 1 5/8, since I have to buy a new pump, and the 1 3/4 is atleast twice as much, whats the advantages of going with the larger pump? I am going to get it tomorrow, but need to know which would be the better. I thought maybe shoebox would know,

thanks
Jason

 

It is a 5/8" or 3/4" pickup tube diameter..... not 1-3/4" or 1-5/8".
The 5/8" pickup has been standard on most small block Chevy engines since '55. The 3/4" was used on some high performance models. The '95up LT1's have the 3/4". I believe all the earlier ones had 5/8". With a stock volume pump you will not likely see a difference. Just match the pump to your existing pickup.

 

thats what i ment to put, 5/8 and 3/4, i don't know what i was thinking, it's been a long day. I have a 3/4 pick up that i used on the high volume pump that's in the car now. Good news though, I raised the engine up with a hoist, took off the y pipe, starter, oil cooler, and the pan fell out on the ground. I couldn't believe it, i thought I was going to have to drop the subframe and all sorts of stuff, and the thing fell out on the ground. i will get a new pump tomorrow and put it in saturday. I was be able to tell for sure if a high volume pump causes problems or not. At this point, I'm saying its a good possibilty.

Jason