What is your opinion of a TBI motor? (305 V8) Worthy or not?

 

it sucks.

 

TBI: Under-rated. Mis-understood. Never properly executed by the factory (in 3rd gens, at least). Best wet-system EFI out there. Good enough of a concept that outfits like Holley base a retrofit EFI system on basically the same thing GM did. Has a bunch more potential than most people would ever give it credit for.

I've never had one (but know people that do). Considered retrofitting the van for better mileage/power for towing, and the 396 for more consistent control.

TBI motor - good driver, terrible performer. For performance, heads horrible, cam horrible, exhaust horrible.

You can work with the TBI, though.

 

i'll rephrase:

the concept of TBI is fine.

the execution of TBI on 3rdgens is horrible.

 

It's not as tempermental as most people portray it as being. I found it easy to work with and even though it is a MAP system it seemed to compensate pretty well to modifications without changing the PROM. I built up a 305 TBI (5-speed) in my now sold 89 IROC vert with polished World Products 305 S/R Torquer heads, Comp Cams factory roller cam with 270* duration and .450/.480" lift (with 1.5's), went with a full aftermarket ignition setup and bolted on some headers and exhaust. I didn't bother with AFPR or a custom chip. It ran really well considering its rich condition. I would regularly lay a beating down to my friends 69 "built" 350 Chevelle and other friends "built" notchback Mustangs; 2 to be exact. One of the Stangs was running 14.0-14.2 depending on track conditions so I suppose I could have been in that range. It did feel like a mid to high 90mph car but probably not since it was only a 305. I never did take it to the track to try it out but I did G-Tech it at 14.4@98mph on my best launch. But we all know how inaccurate G-Tech is anyway.

 

makes for a nice daily driver unless you are looking for performance. not enough result for the amount of work it takes to make them perform ok.