fadetoblack

I have decided to switch over to the Holley 4-Barrel TBI unit controlled by the EBL computer.

I have two questions.

1. What intake manifold would you suggest? I know that in requires a square flange intake manifold. I also do not want to change the factory Formula hood. I know that hood clearance can become an issue.

2. I know that there have been problems with Holley injectors in the past. Should I plan on replacing the Holley injectors with GM injectors? I know that some people would say wait till I have a problem before I try to fix it. But, I have decided not to skimp on any part of this upgrade. So, if there is any doubt that anyone knows about, I want to go ahead and replace them.

The car is a 1990 Firebird Formula with a 383 Stroker. It is used as a 'semi' daily driver. I drive it 3 or 4 times a week. I also plan on taking it to the local drag strip every now and then. I want the best compromise between both situations.

Thank you for any and all of your continued help!

BMmonteSS

The holley injectors to avoid are the onces with the round black plastic caps on the top of the injectors. Those are the flaky chrysler injectors to avoid. The ones without the caps are conventional injectors that can take increased fuel pressure. If you're buying your TB new, it should have the better injectors.

As for the best intake and hood clearance, that's a tuff one. The best intake for an engine operating below 6500 rpm is the performer RPM, hands down. It only gives up 5 HP above 6K to the victor Jr. and makes a ton more torque below 6k. The problem as you know is hood clearance. If you went with a carb hat and a cone "cold air" style filter system you might be able to get it to work. It would suck to buy all the parts and not be able to get it to work. Your next best option would be a low profile single plane like the wiend or the torquer II. The runner length is a bit shorter than the performer RPM, but it won't pose a restriction like the regular performer or any of the other low profile dual planes will. What size cam are you running? If it's tuned primarily for upper RPM's then you might just be ahead to go with the single plane.

You also have to remember that TBI doesn't need a strong vacuum signal to function properly like a carb. So you're not going to have the same throttle response problems like a carb has on a big single plane. TBI is not immune to the sonic tuning of runner length though, and you still have to take that into consideration when choosing a manifold. In reality, as long as your intake isn't posing a flow restriction sonic resonance isn't going to make or break a combo, it's just going to move the sweet spot around a bit.

RBob

iTrader: (1)

As for hood clearance, a stop on the carb board may be of help. See what manifolds they are using that clears.

RBob.

fadetoblack

Thanks for the info!

BMmonteSS ....... I was going to run the Comp Cams Extreme Energy 274.