1991 RS 305

car, 91 rs w/ 305. I'm throwing vortecs that were milled to 56cc. Gaskets are .015" thick. Cam is 97 lt1. Car is a manual, has 3.08's, will have 3.73's someday. I've done tons of research and decided to go from TBI to carb. Here is where the questions come in:

I'm going to run a Holley 650 DP. Intake, well probably the Performer RPM. I'd love to run the Air Gap, but research makes me think I may have clearence problems. Yes It can be made to fit with a drop base air cleaner, but will the top of the air cleaner be getting so low that it is now restricting air flow over the carb? Any opinoins here?

Next, I understand that I should get a vac advance dist. A reliable person very framiliar with thirdgens said that it was possible to un-hook the injectors, get the carb in there, still run the stock distributor, allowing it to still make all timing adjustments with the knock sensor and what not. Question here is would I still then need programming to get the most out of the new combo... with timing adjustments and what not. Probably easier to just get the vaccum advance unit, just thought i'd throw it out there.

Last thing, The pump. I see people making claims of some serious power using the stock TBI pump on a carb... using a regulator with a return line. I'm assuming the pump can deliver the volume needed for a carb.

Thanks for any input!! Matt

camaronewbie

As I understand, the Holley's are more tunable, but thus also REQUIRE more tuning. Everytime I touch a carb I mess it up. If you haven't gotten the carb yet, and would rather not fool too much with one - consider the Edelbrock 1406 - it runs out of the box with very little adjustment, has electric choke, and is avail from Pep Boys for $260 brand new!

The Performer RPM is the same dimensions as the Air Gap - check it out on the Edelbrock site

I have a Performer RPM under my stock hood and I don't think mine is restricted much. I had to use a 1/2 inch spacer and a 2 1/2 inch element to get it to fit over the choke/linkage and under the hood.

Can get a new Accell HEI dizzy at Autozone for $125 (brown cap) - that's brand new in the box with cap, rotor, and even extra springs and weights for tuning - but coil is required. Then, toss the ECM altogether - way easier than trying to tune chips and figure out what the ECM is doing.

My carb (Edelbrock 1405 600cfm) gets plenty of fuel with my stock TBI pump and the Mallory 3-port return style regulator.

1991 RS 305

You Rock.

five7kid

iTrader: (14)

TBI pump - From what I understand, it will be your first weak sister. Go ahead and run it until you find out it is inadequate. If it's been replaced, it may be fine already.

Holley tuneability and need to tune - Last season, running from mid-April to mid-October, I adjusted the idle mixture and idle speed at the beginning of the year. I readjusted those in early September after going from an Action+ intake to an RPM Air Gap. It may not have been "optimized" thoughout all that, but it didn't cause running problems, either.

What carb you run really depends upon how you run the car. For the street with an automatic transmission, the Performer is probably fine (although a q-jet would probably be better). For the strip and/or manual transmission, it's hard to beat a double pumper.

camaronewbie

There - now you have it from the expert - I've seen Five7kid answer all sorts of questions, and he's da man!

I always just heard (and mind you "they" say alot) that the Holley's were more tunable, and hence needed more attention, and that the Edelbrocks were for idiots like me lol - so I went Edelbrock and I'm pleased (which is the bottom line - pleasing the one that spent the money, right? LOL).

On the manual tranny stuff, I know nothing - last one I had was a 1972 Toyota Corolla - talk about a dog! LOL

five7kid

iTrader: (14)

Let me rephrase that - "Go ahead and run it to determine whether or not it is inadequate."

elky74

For clearance on the bottom end, Eddy's 1221 deep flange air cleaner will clear the electric choke on a 1406 carb. Not sure yet about hood clearance though, but you can always get a shorter filter element. They come with a 3" paper element. I bought one for my LeMans but couldn't use it, not tall enough for the throttle linkage. Now, I have a hole in the hood liner where the air cleaner stud pokes thru with a flat base cleaner and 3" element. Incidentally, I ended up putting the 1221 on my Elky and it barely clears the HEI (350 sbc).