Hi Guy's,

I have a project I'm working on. Currently the car has a 1987 305 TPI with MAF. Its wired with a painless engine harness. The 305 is completely rebuilt. Its giving me loads of problems getting the engine to Idle and run right. I was looking at converting it over to carb. My friend gave me a Holley 650CFM part # 7002-1 which is a spread bore carb. I already have a HEI distributor from an earlier engine pre 86.

Is there any reason why I can't use the earlier HEI distributor? I've read on here about different gear hardness between a roller and standard cam. I still have the computer controlled distributor that I can swap the gear from.

Will I have to change the Camshaft?

I've seen an intake manifold for the spread bore for $100 and the Mallory fuel regulator with the return for $80. Looking at performing the swap as cheaply as possible. Thanks

 

You won't have to change the camshaft. You should be able to use the earlier vacuum/mechanical advance distributor if it is in good shape.

You will need to find a "geometry corrector bracket" for your transmission throttle valve cable.

And, you'll probably need different throttle cables.

 

Why not figure out what's wrong with the engine first before you throw the kitchen sink at it?

If there's a physical problem with the engine then a carb swap isnt going to fix it.

Ohm out the fuel injectors. They should measure more than 14 ohms when cold and when warm. If any are less than 12 ohms when warm you have a bad one.

 

I have done the same thing with my 90 GTA. I ripped out all computers and put a 600hp 383 in the car. I have snapped 2 throttle cables already. Is the Lokar stuff going to work? I find it hard to beleive that there is no one who makes a cable that will fit and mount to an AED carb (Holley). Thank You

 

You probably had the cable over adjusted. I did the same thing with a holley on a car I use to have. I just used the factory throttle cable for a carbed car to replace it and it worked just fine.

 

Back from the dead after I found it while searching.......





This is the exact senario I'm dealing with right now.

Motor
originally an 88 LO3
Has 87 305 TPI Cam
84 416 heads ( slight porting )
1.6 roller rockers ( non self ) / roller lifters, rods
Stock V8 intake / 1406 Edelbrock
Aftermarket vac advance Distrib ( pre 86 )
L69 manifolds-cat, Flowmaster cat-back



I dropped the distributor @#1 yesterday then remembered reading that the roller Cam was not a good match for the distributor gear on early style distributors. I thought the same things as 'aldixie'....... (" **** - I need to swap the distrib gears !" )

Do I need to pull the vacuum advanced distributor and swap the gears with the distrib gear on the original 88 distributor, or can I move on and wire this sucker up ??

P.S. ANY advise on timing ?? Stock block with TBI heads wanted '0' degrees,... but the heads are now 416's & the 87 TPI Cam used 6 BTDC. ( using platnum plugs - no gap ).

Thanx in advance !

 

GM recommends using a "melonized" gear with factory-type roller lifter cams, which they started using sometime in the 80's. Your '88 distributor gear will be of that type. If it fits your earlier distributor (I'm not sure if the shaft sizes are the same - probably are), then it'll work fine. Most aftermarket distributors are compatible with factory type roller lifter cams.

 

Thanx for the quick reply Five7,.......... I was pretty sure it needed to be done - but felt the need to check first !

I've got another question for Ya'..... The Distrib I was planning to use is the only Distributor I've currently got with a vacuum advanced can on it. ( Don't know what it was originally used on. ) When I pulled it out to mess with it I could not understand what I was looking at.

I have NEVER seen a distributor with an ECM plug AND a vacuum canister on it before. I never even realized it was like that till today. Is this thing a Vac advanced distributor or not !?! The module looks like it's got 2 pins on one side and 3 on the other. I didn't disassemble it - just took a few quick pics.






The car will have NO ECM. Can I use this distrib ??

 

That was used in non-feedback/knock sensor vehicles (trucks I'm sure of, others I'm not). I had an '84 full-size van with that distributor, someone had disconnected the 4-wire connector and jumped two of the wires (can't remember which two they were) in a vain attempt to get the 305 to run better. The poor engine was overworked in that big vehicle, a 350 long block was put in it just before we got it, I connected the connector back up and removed the jumper, it ran just fine (same either way).

I think you can put a regular 4-pin module in it and make it work (I don't know of any aftermarket support for the 5-pin module). Or, try jumpering two wires at a time until it sparks.

Or, set it up for knock sensor. . .

 

Thanx again Five-7, I REALLY appreciate the info !

I gotta' ask since I have your ear, I'm guessing that I should set the timing @ 6 BTDC due to the head swap,....... ( TBI heads swapped for 416's ) Is 6 degrees the right place to start ?

Thanx again !

 

More like 8-12 at idle w/o vacuum advance hooked up.