I am installing a head/cam swap on 96 LT1 M6 car with a used set of stage
1 or 2 heads and 218/224 comp cam. I 've got a set of GM 28 lb injectors to install with the swap. Some people seem to prefer to go with adj fuel press regulator to richen the mixture up instead of bigger injectors. Which method is better and why?
Thanks.

 

If ya go with the FPR that is adjustable better make sure ya got enough pump. Same with 30-32-36lb'ers The 28lb ya mentioned will flow the same as LT1 at LT1 factory FP. They are rated higher 'cause they are rated with more FP.(LS1) Either way ya will need a tune and the DC can be fixed for larger injectors when ya get the tune.

 

You cant richen the mixture with a FP reg because the ECM will correct for it, except for a few WOT/open loop conditions.

You can make the injectors have a higher flow potential though, like 28s act like 30s etc. Either way, you need to tune the car to get it more or less fuel.

 

Larger injectors are the right way to do it, even if it weren't for the fact the stock injectors don't like being overpressurized. Also using pressure will make your tuners job harder. Stock injector sets are allowed to vary by as much as 10% flow and are 10 years old now. A performance injector set will usually be held to a 3% variation.
There are few actually useful reasons to use an adjustable regulator on this car some guys do use them as a bandaid for the wrong injectors, most just use them out of ignorance.

 

I guess I ment increased flow not mixture. Either way bigger cam/heads need more fuel, usually? From what I've heard FP regulator is one way & bigger inj is another. I got these LT4 injectors (used approx 45k miles) which are supposed to be 28lb from what I read? Right? It seemed like that would match the cam 218/224 size/need? I saw some 28lb racetronix for around $200, would those be enough better to warrant the cost? I do understand the tune will do most of the work for fuel/flow ect... Just wanting the recommended set up inj's vs. fp-reg or both so the tune will work the best and not lean out the motor on the top end ? Thanks...