I have a chance to get a brand new Holley TBI, I think it is the 670 cfm one. It is model 3210, but they have many different part numbers for that model. The one I can get cheap is part #502-7. It says it is for 88-91 Chevrolet and GMC 4.3L. But, I don't see any offered for a 92 LO3. First of all, will this work? Will I see any gains and and is it worth it? Thanks!

 

http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSFI/502-7.html

 

I am not too sure about the 502-7, but I do know for a fact that the 502-6 works fine with a 350. The 502-7 probably is the same unit with different injectors. I would think the 502-5 is the one for the 305.

 

The 502-5 is the holley 670 for the 305. It comes with 57lbs injectors and an AFPR. It's advertised for '87-'89 TBI trucks but it should work just fine on your '92. It works great on my '90. The only thing you need to change is the throttle bolt (relocate it on the opposite side of the throttle arm), adjust the kick down cable, and by the little bolt thingy to get cruise control to hook up.
This unit goes for $289 at Auto Zone (ordered), so if you can get on cheaper, I say go for it, it helps the top end quite a bit.

 

The one I can get is the part # 502-7. A buddy is offering it to me for around $150. I need to know if this will bolt up fine and work? Also, is it worthwhile for performance?