Engine Build - ran into a hang up with TBI intake, need help

[Mattchu60]

I have been building a 355 for my truck for a few weeks. Trying to do it right and use good parts and not get too crazy with compression or wild cams. Using a 12-388-4 Comp Cam and 9:1 compression. I use the truck for towing and want to run 87 octane.

I ran into a issue. I have the heads for the engine already. I thought the TBI heads used a traditional intake pattern but I am finding out now that they don't, so my stock intake wont mate up to the heads. Thinking about ditching the TBI all together and going to carb, since I would need to spend more $$ to tune the TBI ECM anyways.

What are thoughts? Ditch TBI? Will I be happy with a carb? Feel very confused on how to move forward. I cant find an intake on the market that fits pre 87 heads and a TBI.

 

[SkinnyG]

You could run an early-style intake, and a TBI adapter.

 

[bucket]

You could run an early-style intake, and a TBI adapter.

Yep, cheap and easy.

 

[Daveo91Burb]

Yep, I agree that the adapter would be the way to go. Lets you keep the TBI and use a relatively cheap and very common E-brock performer intake or similar - even a pre-87 stock cast iron unit. The adapters are about $50 or so on e-bay, lots of different options. I think Jegs and Summit carry them, too.

The different intake manifold patterns can be a hassle. TBI was the first change, but then the next iteration vortecs changed it again to only 8 bolts that are vertical instead of angled. That's the issue I'm dealing with since I'm building a vortec headed TBI motor for my 91 burb. I ended up buying the GM vortec intake for a spread-bore carb (q-jet) and a TBI adapter. Haven't built it all up yet, but it should work.

 

[Mattchu60]

Thanks for the replys. I was thinking about this last night, I have a few other questions:

- if I was to remove the TBi system, I know I would lose my timing control and my 700r4 Lockup. What else would be affected?

- Would I lose my factory cruise control? I did a search, I believe that the 87 model had "cruise control III" which appears to be separate system from the ECM. Does anyone know if the TBI ECM controls cruise in any way? Would it still work after the TBI is gone?

- Is my HVAC affected? I have A/C and would like to keep it, my guts says this is a separate system.

 

[68post]

http://tbichips.com/?page_id=73 Go here to learn more about TBI in trucks, it is the best website for info I've seen concerning TBI.