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FYI. 37047817 is the OE GM part # for the fuel pump push rod. It was used in all SBC and BBC engines that used a mechanical fuel pump. It's still available. Even from GM dealer parts departments. 3704817 fuel pump push rod
Last edited by sunflower 1972; Aug 11, 2024 at 12:44 PM.
So, I got the new Comp Cams 4610 fuel pump rod in and all appears well. I did a test drive and while the car starts and runs well up to 3000 rpm it stills has the power “falling off” around that rpm. I replaced the mechanical fuel pump but plan to hook my fuel pressure apparatus back up to verify fuel pressure.
One thing at a time!
I’m going through this right now. I bought the older comp cams bronze tip to use on my zz502 cam 454. I was told it was best! HA. Now I have read all the inter net stories about mushroomed ends and can’t get the old one out. Because a bbc in a C2 is not the easiest to r & r a fuel pump I really would like to get it right the 1st time.
Now, for what it’s worth, about .02 cents give or take, I’ve read that GM Perf uses a special steel fuel pump rod in ZZ motors with steel cams to avoid warranty problems.
Anybody ever heard of this?
I’m going through this right now. I bought the older comp cams bronze tip to use on my zz502 cam 454. I was told it was best! HA. Now I have read all the inter net stories about mushroomed ends and can’t get the old one out. Because a bbc in a C2 is not the easiest to r & r a fuel pump I really would like to get it right the 1st time.
Now, for what it’s worth, about .02 cents give or take, I’ve read that GM Perf uses a special steel fuel pump rod in ZZ motors with steel cams to avoid warranty problems.
Anybody ever heard of this?
Dump the mystery; why not download the instructions/install pages for what ever you pick any ZZ4-up motors from Chevrolet Performance site ? Pick the deluxe full everything versions as it will have a fuel pump. Also, CT crate 603 (now discontinued) it had the ZZ roller cam and ZZ4 aka x113 heads. (it ain't special!) https://www.chevrolet.com/performance-parts/owners-support/installation-guides
Thanks, went through all that twice. No Zz fuel pump push rod listed. Several mentions of fuel pump boss and electric fuel pump though.
sure it is. I'm looking at it. sheet (aka page) #2, Item #4,
"push rod, fuel pump" (column GM Part Number) 3704817
3704817 is also very same P/N as in Flat Tappet motors. It ain't special! https://www.chevrolet.com/content/da...12499712-1.pdf
GM's roller cams in Production motors and in race crates are made of a relatively mild billet steel (typically sae 5150) and those use that same ole same ole FP pushrod.
Last edited by Rebelyell; Jun 29, 2025 at 10:37 AM.
sure it is. I'm looking at it. sheet (aka page) #2, Item #4,
"push rod, fuel pump" (column GM Part Number) 3704817
3704817 is also very same P/N as in Flat Tappet motors. It ain't special! https://www.chevrolet.com/content/da...12499712-1.pdf
GM's roller cams in Production motors and in race crates are made of a relatively mild billet steel (typically sae 5150) and those use that same ole same ole FP pushrod.
Yup, so very true. And, thank you for that. All I've contributed is link to motor's service replacement parts lists (direct from the General's mouth). And a bit of basic, but hard-won metallurgy.
For further proof, one need only review GM's own parts lists for both flat tappet & roller lifter motors; not all such lists are comprehensive and may require reviewing several (t shirt).
I cannot vouch for alloys of CPP/GMPP Off-Road Performance roller camshafts; only for cams in GM serial production motors and some GM race crates. This "what pump rod" should I run challenged me years ago as well. For those running sae 8xxx and/or 9xxx alloys, My above does Not apply!
I talked to local Chevy dealer High Performance guy today. He confirmed the fuel pump pushrod is correct for GM steel cams but not all makes of steel cams.
He also said some of the problems arise from high pressure pumps (more spring pressure) and higher rpm’s.
What happens is the heavier stock pushrod starts bouncing back and forth on the cam lobe at higher rpm’s, creating a “lofting” effect which pounds the cam causing the problems.
So that is the need for the lighter push rods.
Sounds reasonable to me.
