I don’t think that motor and turbo combo made 850whp with the fuel setup you’re describing and is the pics.
The easiest setup going is a Walbro 450 attached to the stock pickup (with minor modifications) and either a budget or high quality FPR. It will handle 500whp safely, repeat safely, all day long.
I believe Racetronix makes a nice dual pump drop in setup, but it’s pricey.
And I don’t want to argue / start poop, but there is no way you made 800 on a 255 Walbro. And for that matter that is a tall order on 2 255’s. And if they weren’t boost (manifold) referenced like you picture shows, then it would 2/3 of that.
Oh but it did and is well documented. Like I said I did it myself and the article is in Vette Magazine shows when it was at 745 rwhp on 14psi. Then I ran it on the dyno for the A&A Corvette party and it made 815rwhp. I was also one of the first to use HP Tuners 3 bar Speed Density software, with the car appearing on HP Tuners website. If you re-read my mods it was an LPE 255 walbro pump with Ken Bell Boast a Pump (one wire) and the other mods I mentioned. 72psi at 6700 rpms, non boost referenced at 18# psi boost, tuned on Sunoco 100 octane pump gas. With the boost controller off on the stock waste gate springs 8.75lbs, and 91 octane it was making 590-610 whp depending on whose dyno and day etc. Below is the dyno graph from the Vette Magazine article in Dec 2005, the initial tune with HP Tuners Speed Denisty 3 Bar software is in black. Made 834 whp, all with the fuel system exactly as I have pic'd and described above..
I have been away from LS1s for 10 years now, as I've been busy with my C7Z and Maggie 2650 mods and have probably forgotten more about the LS1/LS6 then most people, but with all of the updates from when I was helping pioneer the first ATI Procharger D1 (in the U.S.) back in 2002, and twin turbo systems, it is nice to see all the support now for resto mods and LS1 swaps and experience and products available. So I look to those that know about it like people did with me earlier with the C5 Corvette and forced induction mods.
I also attached the video making over 800whp. Funny thing is I didn't know the individual filming, he sent me the video on the Corvette Forum. Andy's dynojet I think was a 248x rated at 1100hp, at over 800whp I was pushing the limits and you can hear how high the dyno winds up at the end of the video. Nobody else's car that day made the dyno sound that way lol. Final tune was 850whp about 6 mos later after I removed the Borla cat back mufflers and replaced with Corsa straight pipes. But all that was also through 2.5" exhaust. The reason it is quiet at idle the PT52 T4 turbos muffle the sound until it is full spool.
Looks like I can't attach the video, trying to link. Dyno run starts at 3:15....you can hear somebody say, "it made less this time", that is because it was the 2nd pull and everything was heat soaked from sitting, first dyno pull was 840 whp. It's hard for me to believe it has been over 15 years since these videos, I appreciate you questioning my fuel system as it inspired me to go back through my files and look for the history. One of the attached pics shows the specs on the build too.
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