71 Holley LT-1 (4801) power valve numbers

[Mike E.]

If anyone can help with those numbers, I'd appreciate it. I don't have a Holley book, and my parts store is primarily computerized and doesn't have a clue on this one.Thanks!

[Paul O.]

Re: 71 Holley LT-1 (4801) power valve numbers

Hey Mike we met each other at St. Charles Nationals really admired you LT-1. Mike the best way to select a power valve with the engine warmed up and at idle check the vacuum if it lets say 13" Hg divide that by 2 gives you 6.5" that's the power valve you need. Holley power valve numbers are the last 2 digits in the part number so like 125-165 is 6.5" PV. Hope that helps I think that a 6.5" would be correct but it's best to check your vacuum first. Paul 18046

[Cleet H.]

Re: 71 Holley LT-1 (4801) power valve numbers

mike,
i have an lt-1 (4801) in a box at home, so it would be easy to get to, the problem is i don't know what a power valve is. let me know what i'm looking for and i'll check it out when i get home.
cleet

[Tom L.]

Re: 71 Holley LT-1 (4801) power valve numbers

The power valve is screwed into the primary meterng block. The Primary (front) bowl and metering block must be removed to get to it. It will be screwed into the side of the block opposite of the bowl. The number should be stamped into it on the diaphram side. This picture should help.

[Joe L.]

Re: 71 Holley LT-1 (4801) power valve numbers

If anyone can help with those numbers, I'd appreciate it. I don't have a Holley book, and my parts store is primarily computerized and doesn't have a clue on this one.Thanks!

Mike-----


The power valve should be a Holley #125-85, aka GM #3852485. The GM part is discontinued.

[Joe C.]

Re: 71 Holley LT-1 (4801) power valve numbers

If anyone can help with those numbers, I'd appreciate it. I don't have a Holley book, and my parts store is primarily computerized and doesn't have a clue on this one.Thanks!

http://www.holley.com/data/TechService/Technical/Carb%20Numerical%20Listing.pdf

[Mike E.]

Re: 71 Holley LT-1 (4801) power valve numbers

Joe--
Just a quick clarification, if I might ask. Is both the primary and secondary power valve a 125-85? The primary one we took out looks to be a 65. No idea if it is original or not. The Holley site is giving my computer fits--get an error message every time I hit the power valve icon.
Thanks.
Mike

[Paul O.]

Re: 71 Holley LT-1 (4801) power valve numbers

Mike I looked at the Holley site for you a 4801-1 lists a 128-85 for the primary and secondary power valves. As always Joe was right on the numbers. Paul 18046

[Joe L.]

Re: 71 Holley LT-1 (4801) power valve numbers

Joe--
Just a quick clarification, if I might ask. Is both the primary and secondary power valve a 125-85? The primary one we took out looks to be a 65. No idea if it is original or not. The Holley site is giving my computer fits--get an error message every time I hit the power valve icon.
Thanks.
Mike

Mike----

As far as I can tell, they are both the same.

[Joe C.]

Re: 71 Holley LT-1 (4801) power valve numbers

Joe--
Just a quick clarification, if I might ask. Is both the primary and secondary power valve a 125-85? The primary one we took out looks to be a 65. No idea if it is original or not. The Holley site is giving my computer fits--get an error message every time I hit the power valve icon.
Thanks.
Mike

Mike,

Do you have Adobe Reader installed on your computer?
If not, then you won't be able to read items in pdf (pagefile) format.

I will back up one page for you, and let you try again from there:

http://www.holley.com/TechService/Library.asp

from here, click on "Carb Numerical Listing"

The PV is misprinted in the listing. It reads "128-85" but all PV's have a "125" prefix, so should be "125-85".