I've been poking around other folks threads trying to learn a bit...time to start my own here:

So if I decide to jump from 150 to 250 shot I need to:
1- Change fuel pump (LS1) Walboro 255 or equiv
2- Add second stage
3- Change timing
4- (poss) Raise Octane

Question 1: Am I correct so far?
Question 2: What's involved in adding second stage. Is it better to go to a fogger? Are second nozzel okay?
Question 3: Does timing have to be adjusted variably.
Question 4:

 

What system are you using?

 

Currently switching over to an NX MAF...this is a learning excercize though...i'm sticking with my 150 throughtout the fall early winter....

 

I do it on a single nozzle w/Maximizer II. I got the Racetronix pump kit though.

-somebody

 

Are you still running a stock bottom end or not? A 250 shot is alot for a stock bottom end and it is somewhat of a gamble.

You will need more than a just a Walbro pump alone. My Walbro is taxed on a 225 shot, I just added a voltage blaster and hotwire kit in hopes it will support a 250 shot, we'll see.

I would do a second dry stage. I would be alittle concerned about fuel distribution issues putting a wet 250 shot through the intake. It can be done but I feel the wet/dry combo with a big shot is just safer than one big wet shot. You would need to upgrade injectors though if you wet wet/dry.

You will absolutly need a major timing adjustment.

You will absolulty not want to be running that 250 shot on pump gas, especially with non forged internals (doesn't leave much room for error). I would stick with a minimium of 100-104.

You will also want to look at replacing your rod bolts, they would probrably be the first to go.

 

This is what I 'm looking for...I may not have the nerve to do anything more than a 150-175 on my stock bottom. We are really just looking to the future.