A word about bored out T-body's

[88-383]

JFYI,

I wont give the names, but I've had to swap out a few because they were screwed up.

The first one came from Ebay and was bored to 46mm. The unit looked great and I bolted it right on. The truck started and idled fine, but when I hit the gas, it stuck at around 3Krpm. I checked everything and even put in a new cable. With the engine off it seemed fine and snapped back nicely.

After removing it and playing with it I noticed the shaft was loose on one end and allowed the blades to bind esp with vacum pulling on it.

The second one came out of Southern CA. This unit looked hot also and passed my inspection from lessons learned above. This time the truck started and reved-up with out sticking.

I didn't find the problem with this one till I started tuning the truck. The problem was that my truck was hopelessly (spelling) stuck in limp home mode! I found my TPS voltage was WAY down. Turned out the shaft was installed incorrectly, or atleast the little lever that actuates the TPS was not in the same position as my the stock T-body. It was indexed so that the little lever was more "rearward" than stock postion.

I had to fab up something to take up the slack. Didn't feel like R&Ring another at this time.

Kelvin

 

[dyeager535]

I believe there is an article out there that someone else has written detailing similar problems with bored TB's. The big block one is probably a better swap, although I don't know if 46MM is bigger than that.

 

[Creek]

The 454 TB has 2" (50.8) bores. That is what I have on my 383. I agree with Dorian, it's a better choice.

David

 

[Col_Sanders]

Glad I saw this and thank you for sacrificing some of your hard earned $$ to test. Looks like I will find a big block TB or continue my search for a cheap Holley.