GM 7.4L TBI to Vortec Conversion

[Vacationer04]

Has anybody attempted a TBI to Vortec conversion? When I bought my MH in 2004 I was told to buy a '96 or newer to get the Vortec but wasn't told to make sure the chassis was also the same year. I wound up with a '96 Pace Arrow with a '95 chassis and therefore a TBI engine instead. While it runs great and gets repectable 7+ MPG it lags a little on HP on hill climbs. I recently replaced my '96 Tracker (2400#) with a '98 Jeep Cherokee (3200#) and the additional weight has me curious if it can be converted relatively easily or will the electronics be such a hassle to make it unreasonable? I have access to several self-service salvage yards to procure parts that would make that easy. Just don't know how much of the electrical sytem would have to be altered.

[timmac]

Gjac wrote:
I have a 96 also with a 95 TBI. For about a $1000 you can install headers, mufflers, and a cai and increase the HP from 230 to 300 which would be more cost effective than changing engines unless there is something wrong with your existing engine.

I would agree with this post here, no need to get rid of the TBI, its a easy system to work on, Vortec also had different heads as well as fuel inject, you can change out the stock TBI for a performance one from Holley, nothing wrong with a TBI, my neighbor has one and it still runs fine and pulls a 18,000lb FW.

[Gale_Hawkins]

sum1 wrote:
If you enjoy such projects and have the time, go for it, I don't have time. I put a Harris Performance chip TBIchips in mine after discovering a timing curve glitch in the stock chip. The chip made an undeniable difference in performance, economy, temperatures. I run hi-test, as well. I now pull 6 and 7% grades at 21,000 pounds. Brian runs a one man show and was very responsive. He can burn custom chips to suit your needs, as well.

In working with Brian I was impressed. He knows 454 TBI from personal ownership over the years as well. He was the one that called our miss and back firing cause correctly. He said he expected the Pick Up coil under the distributor and was correct. It was a $15 part at O'Reilly's but it was a heck of a job at the time because the twins were only nine but they helped make it happen because the they had asked for a MH. 🙂 Those were fun years for sure. If it had not been for Brian's knowledge and help we would have been stuck for a while.

What some of us are trying to communicate there is NOTHING wrong with the 454 TBI design and was a quantum leap forward over the carb which is still a good system. The 1992 TBI system has needed nothing in our case and is still performing like new. Love the no choking part. 🙂

[Gjac]

I have a 96 also with a 95 TBI. For about a $1000 you can install headers, mufflers, and a cai and increase the HP from 230 to 300 which would be more cost effective than changing engines unless there is something wrong with your existing engine.

[eHoefler]

You can install an aftermarket fuel injection kit that stands alone, does not use any of the OEM computers. I installed an Edelbrock port fuel injection on a stroked 383 small block in my 1983 Chevy pick up. It cost me $2300 for an engine with Vortec heads. The non Vortec was just under $2000. Performs very well and increased my fuel mileage 3 miles a gallon.

[bucky]

Two totally different animals other than some of the short block. The Vortec coincided with the introduction of OBD2 emissions while the TBI was still OBD1. Possible sure, but the dollars spent would be insane. Your TBI can be improved for far less. BenK is probably the best source for info on the early 454s, I would search his posts.

[sum1]

If you enjoy such projects and have the time, go for it, I don't have time. I put a Harris Performance chip TBIchips in mine after discovering a timing curve glitch in the stock chip. The chip made an undeniable difference in performance, economy, temperatures. I run hi-test, as well. I now pull 6 and 7% grades at 21,000 pounds. Brian runs a one man show and was very responsive. He can burn custom chips to suit your needs, as well.

[Gale_Hawkins]

You just need to trade up if you want the Vortex in my view. We have a 92 454 TBI and it is very strong especially if burning 93 octane which does not cost any more than 87 due to the increase in MPG.

What is your timing set on? A 454 can be a dog is the timing is off and sadly there are fewer techs that know how to tune pre OBCD II engines today.

Seriously you have a fine engine if it is tuned up well and is preferred over spending a few thousand dollars to hack to multi port injection.

The Vortex makes more power due to the cam and better breathing intake heads.