I recently picked up a car from another forum member with a forged 370" LS3 headed motor. I still have the pewter hardtop in the sig, and I'm trying to figure out which car to keep (due to exterior issues and the tan interior in the new one), but regardless which one it is, the motor in this SOM car is staying. I'm very interested in tuning it in SD for E85 since it has recently become available in my area.

This fuel is relatively new to me, I've seen how well it works on boosted applications, but this one will be a bit different. It will be N/A to start, with the possibility of n2o in the future. My main questions are regarding injector size, feed line size, regulator (if required), fuel pump and spark plug selection.

Here's the combo...

The engine is a 370" forged bottom end w/ a stock 6L crank
11.8:1 CR
LS3/L92 heads with a fairly recent valvejob (motor has <5k miles on it)
235/242 .637/.615 111+2 lsa cam
LS3 intake, rails and injectors off a 2010 vette
1-7/8" headers
Racetronix/walbro 255 hotwire kit


There's a possibility to having the heads cleaned up a tad (mainly if I swap motors between these two cars), and also the possibility of milling the heads a bit more to raise CR. The potential issue here is PTV clearance. The pistons are flattops with valve reliefs for the current setup - not sure how much more they can be cut - if I even wanna mess with doing this.

There is a possibility of adding a 150 shot of n2o on top of the motor, so I want to build the fuel system to adequately accommodate that as well.

Ideally I'd like to pick up a good 30rwhp with the E85 fuel (timing upped alot), and hopefully an additional 20ish rwhp from the speed density tuning. Currently the car makes 460rwhp thru a TH400 on the motor (with 1-3/4" headers) and is setup for n2o - not sure if that number was with timing pulled for bottle or not. I took the car out last night and it runs fantastic even in its 'weakened' condition. The converter works amazingly well, the shift extension feels about perfect and the car just wants to rev/go.

My thoughts were 80lb injectors, stock LS3 rails (if adequate), 8AN feed (if needed), stock feed as return, Mallory 4305M regulator, and not real sure on pumps. I've ran dual intake walbro 255's on previous boosted applications, but I want to make sure I chose a pump or pumps that will live in e85.

Am I on the right track so far? I searched, but all I found was a few scattered ideas here and there and not a complete proven system that worked with a setup close to mine. TIA.