I am nearing the final part of my new engine build and am wondering what else I have to look forward to that will create problems for me. Let me fill you in as to what we did.
We took a 350 TBI we found in a junk yard that was burried on a bus with many other engines. Stripped it down to nothing and redid everything. We went .030 over on the heads, roller rockers and lifters, radical cam, timing gear, 2500 rpm stall converter, tranny remains 700R4. The rear has a BWposi 3:29, traction control bars and disc brakes. Can I run the car with the original 305 computer? Do I have to use the TBI that came with the 350 or can I use the TBI that came off the 305? Or can I use the 305 throttle body and just swap out the injectors from the 350? I am trying to get away with using the existing wire harness and computer for the 305 and just have a chip burned. The heads are almost identical from either engine.

 

Do you mean 0.030"-over on the cylinders?

3.27:1, perhaps?

The TBI forum has a bunch of info on going from 305 to 350.

305 heads have 1.84" intake valves and 58cc chambers. The 350 heads have 1.94" intake valves and 64cc chambers. Both are the hated "swirl port" heads.

 

Congrats on the swap! i did my swap from my old 305 TBI to a 350 buick roadmaster type H motor. And you can keep the same computer,but you need a different chip. I found that old a while ago. Go to TBI Chips.com and let him know all of your options. HEs a great day and ships fast. And if you need something changed on the chip, you can send it back and he will do it for free. You can use the same Throttle body, you just need to swap the injectors.

 

yea, you are right 3:27. I must have typed it wrong. Its correct in my profile though. Sorry. And yes it 30 over. on the cylinders. This is my first build and man the terminology is nuts. I should have it down by now but still being corrected where ever I go. Just yesterday I ordered a temperature switch and needed a sending unit. Wrong part again. Soon I will listen to my 15 year old son and do the right thing. He is the Brains of the operation. I am just the money man$$$$.

 

What is so bad with the swirl port heads? Can you recommend another TBI Intake that can be used?

 

Swirl ports don't flow. Period. Forget making more than maybe 250 HP with them, unless you get nitrous or boost.
Edelbrock makes a dedicated TBI intake manifold, and Holley makes a version of their Pro-Jection II intake manifold for early heads, and another for later heads.