exactly what the title says. I swapped from tbi to tpi and when the distributor is all the way down but no clamped down you can shake it around a little from side to side. this makes me think that the tpi dist. has a slightly larger base on it. I should mention I am using a superram intake base manifold. any thoughts?

 

Not sure what to tell you. I'm using my L03 dizzy on my TPI manifold. I don't have any problems with play.

 

I have an L98 dizzy in the back of my Edelbrock 4-barrel intake, which had an old vacuum-mechanical HEI in it until a few weeks ago. I also have an LO3 dizzy in my L98 car. They both fit perfectly. The problem must be with your intake base. I'd try sticking the other dizzy in, just to see if it has the same slack in it.

 

Dude, i know exactly what your problem is. I was just reading about this on the website www.chevythunder.com. The tbi motors started using a larger base distributor around 1992 according to that website. There's a picture of the two different distributors, and you can definitely see the difference. If you get a 1991 or older distributor from either a tpi or tbi motor, it should work fine for your application. Wow, it's cool that I just barely read about that and here's a guy with the same problem. I never knew there was a difference until I read that like a week ago.

 

http://www.chevythunder.com./gm_thro...ction_pg_1.htm

bottom of the page is what Pat Hall is talking about. mine def. looks like the left smaller one. so is the superram base bored for larger base? I can tighten down the clamp to keep it from moving but should I switch to the different larger base dist.? my setup is running really rough and I actually have gas comming out my tail pipes and it is really stumbling. unfortunetly I have no error codes poping up so not sure what is going on.

 

The one other theory I have is does your intake have two different threaded holes to put the distributor clamp bolt in? Some aftermarket intakes have dual holes. One on the driver's side and one on the passenger side. Has something to do with magneto distributors or 23 degree heads or something like that. Anyways, one of the mounts is for standard setups and the other is for the different applications. Check your intake and see if there's two different holes.

 

That web site isn't entirely correct.

The wider flange distributor was only used on 91-93 Bcars with LO3 or LO5. Bcars for 91-93 include Chev Caprice, Buick Roadmaster, Olds Custom Cruiser. The 93 Cad Fleetwood also had the LO5. The web site says it was used on some 92 and all 93 TBI engines.... which isn't right. For example TBI trucks in that era didn't use the wide flange distributor.

The intake manifolds used on the 91-93 Bcars had a distributor hole that was larger in diameter so that the dist could be removed under the body cowl overhang without the need for removing the entire intake manifold. The Fcar didn't need that for distrib removal so the Fcars wouldn't (or shouldn't) have received the large-flange distr UNLESS they also got the mating large flange TBI intake.

So the Chevy Thunder was correct in saying that you can't just use any TBI distributor, but they also should have been less confusing by saying that the large flange distrib, as used on 91-93 Bcars, can't be used on an Fcar unless you also use the 91-93 mating intake. More discussion of this appears here. HTH.

 

That makes sense kdrolt. My dad has a 91 caprice, and just replacing the distributor cap and rotor is a PITA because it does sit quite a ways underneath the cowl on those. You can pretty much lift the distributor straight up and out on our cars, so you're right, there's no need for the different distributor. I still wonder if the superram manifold has the dual distributor clamp mounts though (one on each side).

 

so why would I have play on a superram manifold? shouldn't it be designed for the smaller? or would they have had the fore site to design it to fit in any small block car and given it a larger whole for the dist.?

 

I have a 93 k 1500 and the engine in it has the large flange wondering if it’s the original engine got me wondering