chris308

So i'm researching rails and I have noticed that there is an item on stock 99 rails that seems to be omitted from aftermarket setups. I included a pic below...

https://encrypted-tbn0.gstatic.com/i...Kl871CUVXUUa-S

What is this and do I need to replace it? On the 99 the regulator is in the fuel filter in back so I know its not that...

slow ride

It's just a damper and no you don't need it with the larger aftermarket rails. The hard part is fitting the aftermarket rails under the cowl as it usually hits the fiberglass firewall.

chris308

I wonder if I could get away with using an OEM rail like LS3 or LS9 with E85 and not handicap my fuel supply needs?

Shoaf85

Yep I used ls3 rails all last year making 800+whp on e85

slow ride

It also depends on what intake you are using as the ls1, ls6 and early fast intake use the old rail style. I would just add the return on the schrader port and be done unless you have access to a supply/return rail from a 97'-98'. One could also tig weld steel fittings on the stock type rail if you wanted a dual in/out setup for higher power setups.

juice12

I make 840 rwhp with stock rails and e85, Id 2000 injectors

neutron82

I used a -10an xrp fitting the rear of the passenger side rail to feed it and capped off the rear of the driver side rail... it works fine and probably making low to mid 800's... a friend of mine made some custom rails that he was able to feed both of the rails from the rear with -10 hose which was pretty badass but you probably don't need that if you aren't trying to make big power... here is the fitting I used,