Hey Everyone,
This is my first post on this forum, so I apologize if I posted this in the wrong location. Let me first start off by saying that this forum, and Cliffs book has helped me so much in my Q-Jet journey.
I'm wrapping up the rebuild on my original Quadrajet (P/N: 7042208) for my 350 Chevy that is going back into its 1972 Cheyenne 3/4 ton pickup, in front of a four-speed SM-465. This is not a race car or high performance truck by any means, but the engine has been slightly hopped up from stock.
I'm having trouble identifying which accelerator pump to use. Now I know the pump has probably been changed over the years, so I don't know what the original spec was. I have pictures of both pumps below.
1. The accelerator pump I pulled out, and one that I can replace it with has a high spring retainer, and a longer, weaker duration spring. This was the pump that I was going to install first to see how the engine responded and ran. I also had to reuse the duration spring.
2. The second pump I have, is Cliffs HP accelerator pump. It is a tiny bit shorter in overall length, has a much lower retainer location, and shorter, more compressed duration spring. I have searched through some of the existing posts for some information:
https://cliffshighperformance.com/simplemachinesforum/index.php/topic,123.msg533.html#msg533https://cliffshighperformance.com/simplemachinesforum/index.php/topic,235.msg975.html#msg975I see that Cliffs are listed as "HP" pumps, and i'm not sure its correct for my application. It seems these are provided for every rebuild, and i'm sure it would be fine. I know it is superior with the material of the pump cup and retainer spring. It is definitely built better. However, i'm not going to be driving the truck for a while, so I don't want it to sit in the carb if it doesn't have to.
Can someone explain what the difference is and the effect both will have. Is this something I should be tuning and testing on the engine stand? Analysis paralysis...
Thanks so much in advance!
