TBI Distributor Recommendations for Roller Cam

[Daveo91Burb]

Starting a separate thread for some distributor questions. I need a reliable distributor that will go in my roller cam 383 that I'm building. I have two stock TBI distributors, one that came from my '90 parts Burb and the other that's in operation in my '91 now. Should I rebuild one of them, or buy a new one?

- If I rebuild, do I just replace the module and magnetic pick up (and cap and rotor, of course)? Or is there more to it? The shaft in the extra one has very little play so I'm assuming bushings are good.

- Also if I rebuild, do I need to replace the drive gear since I'm converting to roller cam? As of right now, I plan to use a stock, used '96 vortec roller cam. I have read a lot about this on the internet and still am confused. Are the TBI cams the same material as the vortec cams? If they're not, I guess I should replace the gear with a mellonized one? It's like $40 or $50 is why I ask.

- If I go new, I'd probably go with the Delphi:
https://www.amazon.com/Delphi-CZ20001-Distributor/dp/B000CGFJNA
Although I'd probably have to change the gear on that one, too?

- One thing I know for certain: I'll be staying away from the $30 flea-bay chinese junk. I tried one of those for a few years in my Vette -- never again!

 

[bucket]

'87 and later V8 cars got roller cams, with carb, TBI, and TPI. I don't know if the same dizzy in a TBI truck got the melonized gear, but a replacement from the parts store (or MSD) for a car will have the correct gear for sure. Personally, I'd go with a new MSD unit.

 

[Rusty Nail]

I run a Jeg's brand and love it. Even came with adjustable canister! Hot coil, vented brass cap, fancy module...Hard to go wrong.
Very reasonable price, not worth the trouble of rebuild
Plus it's polished and shiny!

 

[Daveo91Burb]

'87 and later V8 cars got roller cams, with carb, TBI, and TPI. I don't know if the same dizzy in a TBI truck got the melonized gear, but a replacement from the parts store (or MSD) for a car will have the correct gear for sure. Personally, I'd go with a new MSD unit.

Thanks - helpful piece of advice. I cross-referenced a 1989 Caprice with 5.7 with my 1991 V2500 suburban with 5.7 on RockAuto and it came up with the exact same list of available distributors! So I think this tells me GM used the same dist regardless of whether it was roller or flat tappet cam? Unless all the replacements just switched over to mellonized gear to make things easier..... Hmmmm. I'm sure MSD would work fine, but I prefer to stay with GM stuff whenever possible, especially if I can rebuild something original fairly easily. If I can keep that original gear, I think it will be pretty easy and not too much $$.

 

[Daveo91Burb]

I run a Jeg's brand and love it. Even came with adjustable canister! Hot coil, vented brass cap, fancy module...Hard to go wrong.
Very reasonable price, not worth the trouble of rebuild
Plus it's polished and shiny!

TBI distributors are a bit different than the carb HEI units. There's no vacuum can or mechanical advance - all the advance is done with the computer. So if I can keep that gear at the bottom (pretty sure I can, see above) it should be pretty simple/low buck to rebuild: magnetic pickup coil, module, cap and rotor.

If anyone believes different that I should NOT use the original gear from my TBI distributor with a vortec OEM roller cam, please speak up!

 

[Rusty Nail]

That's my $.02
It's up to you to see if they have one you can use, Jegs sells great products if you are interested in great products...

 

[bucket]

Thanks - helpful piece of advice. I cross-referenced a 1989 Caprice with 5.7 with my 1991 V2500 suburban with 5.7 on RockAuto and it came up with the exact same list of available distributors! So I think this tells me GM used the same dist regardless of whether it was roller or flat tappet cam? Unless all the replacements just switched over to mellonized gear to make things easier..... Hmmmm. I'm sure MSD would work fine, but I prefer to stay with GM stuff whenever possible, especially if I can rebuild something original fairly easily. If I can keep that original gear, I think it will be pretty easy and not too much $$.

I would ASSUME the trucks got the melonized gear too, but I can't say for certain.

I'm all for rebuilding a stock dizzy IF Delco parts are being used. Otherwise, an MSD unit (which I think are very nice for the money) will be far more reliable that a stock unit with cheapo replacement parts.

 

[Daveo91Burb]

I would ASSUME the trucks got the melonized gear too, but I can't say for certain.

I'm all for rebuilding a stock dizzy IF Delco parts are being used. Otherwise, an MSD unit (which I think are very nice for the money) will be far more reliable that a stock unit with cheapo replacement parts.

Yep, they'll all be either Delco or Delphi, which I think were used pretty frequently for OEM, too. Just got the Delphi magnetic pick up delivered today - looks pretty high quality although it is Hecho en Mexico, but at least it's not Hecho en China!

 

[Daveo91Burb]

Finished my distributor rebuild! All seems well except there is more friction and noise as the rotor passes by one post than all the others. Should I be concerned?

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