I’m a General Motors fan and Truck owner, I like them for many reasons. I won’t go into all the reasons. We all have a favorite brand of car or truck and that is a good thing. We certainly would not want everyone to own the same car or truck. That is one beauty of America, we can choose what we want to drive.
The beauty of what I am going to describe is that you will pick up considerable gas mileage and longer engine life. My proposal is to put a T700-R4 (4L60) transmission into a vehicle that had a 3 speed (T400, T350, T350-C, etc.) automatic transmission in it. The T700 is an overdrive transmission with a lock-up torque converter, therefore effectively adding one or two overdrive gear ranges to your vehicle that has a 3 speed unit and possibly a lockup torque converter in it now
By adding an overdrive transmission you slow the engine rpm’s (revolutions per minute) down with the overdrive gear ranges, thus improving gas mileage and engine lifespan.
FYI-All Chevrolet engines with the V-8 bolt pattern on the back of the engine where it bolts to a transmission such as the 262ci (1955), 283 ci, 327ci, 350ci (1967 to 2004), 427ci, 454ci and the motors with that pattern up until about 2004, will work for this project. The point is all of these engine use the same transmission bolt pattern.
I’m am living proof that this is do-able for several reasons. One reason has to do with the fact that I own a 1988 GMC 1 ton four wheel drive non-duallie pick up. I bought it new. I really don’t drive that much, it only has 94,000 loving miles on it anyway. The thing about it was that it got 10 miles per gallon. No matter whether it was city or highway driving, that was it.
I want to make this part clear, I did this because I could do it, being as I owned a transmission repair shop from 1981 to 2006. however, I always recommend this swap-over when a person with one of the millions of vehicles with this engine set-up needed a new transmission. It is a viable and affordable swap and a direct factory bolt in without any unusual parts needed. A DIYer with some mechanical ability can do it at home.
I’ll get more involved in the parts needed to do the swap over in my next post. For now lets talk about its virtues. First off, my truck has a 5.7 liter or 350 ci engine in it, I went from 10 mpg on the highway to 15 or 16 mpg at about 75 mph. I went from the 10 mpg in the city to about 13 mpg. Not to shabby, eh..
If you are going to pay for a rebuilt original replacement transmission anyway, assuming your transmission has failed, why not spend about 300 to 400 dollars more and have a nice, clean, factory T-700R4 overdrive transmission installed instead. You will recover your money in a year or less with the cost of gas.
I would be calling GotTransmissions.com 866-320-1182 for a T-700R4 that is upgraded for my particular purposes. They are the most reliable and knowledgeable source of transmissions I have found. Believe me, after over 35 actual years of rebuilding transmissions and owning my own shop, it becomes easy to pick out a company that is committed to your success.
Stay tuned to the GotTransmissions.com Blog for the rest of this cool swap over. We will go into more detail tomorrow. Take your time and see what helpful tips and information you may find here in our blog. See you tomorrow.
