which fuel kit do u guys recommend for 600rwhp for greddy t78kit

Use what ever info you need. I put it up for anyone that wants to put together their own kit. The Y block from jegs is fine for fuel. The outlet is a 1/2 nipple. And the inlet nipples I put on have an inside diameter bigger than the pumps outlet. When you look at the pump outlets, I'm amazed they can flow as much as they do. Looks like there is a restrictor just inside. But yes, the block is fine.

From what I read, if you want to feed from both ends on the HKS, it's return is acutally near the end of the rail (between 5/6) and not in the center like the SP. Also, if you want to use different AN fittings, -8 instead of -6, the threads in the rail are a wierd size and finding the right fitting is difficult. The SP uses 3/8 NPT and you can find those in any AN size. Easy to obtain. Larry at SP gave me a fair price on the rail and injectors so I went with that. He supplied me with the siemen injectors and I'm not sure if they fit the HKS rail or if the greddy 720cc injectors that are common fit the SP rail. Both are good injectors. The o rings for the greddy injectors have to be bought seperate and use some grommets I believe, $120 extra. Siemens just use 2 o rings and come with the injectors.

Larry's rail came with no fittings so you'll have to buy what ever AN size you want. The HKS has -6 on each end I believe and you have to buy the return fitting if you want to go dual feed.

Those kits (cheap $$) coming out sound good but were not available when I did mine. I think the cheapest was around $2200 or $2300 and I ended up saving a few hundred.

It's not just about buying the parts. The installation takes a whole lot more effort. Especially if you follow my parts list. I put a lot of extra effort into the installation so it was sound. My braided lines are covered. Fabricated aluminum brackets for the pumps instead of using hose clamps, etc. Pretty in depth project whether you buy the pieces yourself or buy a kit.