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Currently doing a ground up restoration on a 1985 T-Top IROC Camaro. Going with a 440 LSX/LS7 engine producing around 725 FWHP. Because I have been out of the game for several years I'm not up on what trans to use in my build, so looking for real world info based on experience. Want to run an auto and electronically controlled. Have looked at the 4l60/70/ series of units as I'd like to keep from altering the trans tunnel as the car came originally with a 700r4. My goal is strength and durability. Also am running a Holley Dominator ECU to control trans. Car weighs 3600lbs and am using a Moser 12-bolt with 3.55 gearing. So, what stall speed would you guys also recommend? And lastly, can you give me an idea of who to build it? I live in the Houston area and could do local or online sales. I welcome your comments as you guys have answered several questions for me in the past and it is appreciated. Thanks. P.S. A pic of car in earlier times.
You could use a 4L60E with a one piece case. It's the exact same size as the 700R4.
A 60/65/70/79 or whatever with a two piece case fits almost as well. The one piece case can use all of the internals as the best built 60 to 79E, etc.
Jeremy from RPM Transmissions is the one phone call you need to make! I've used them for 12+ years and they have always been awesome and steered me in the right direction. https://www.facebook.com/RPM-Transmi...758266/?ref=hl
I really hope you start a build thread for this car!! I am building an 85 Z28 and an 87 IROC-Z myself. My 87 IROC was my highschool car. Ive owned it for 18 years and I actually have a 440ci LS7 to go in mine as well. I am doing a T56 Magnum in mine because I plan to auto cross it. But I have plans to build a crossmember and build the exhaust around a 4L60e so I can swap in the auto later on down the road.
I would love to work with you on a trans for this build. It is right up my alley. Here are my project 3rd gens.
Yes, great looking car.
Both RPM and PerformaBuilt can custom build you a great 4L65E to handle your power level. However such top-of-the-line 4L65E get quite expensive due to the special parts in them. You can probably save $1000 with a moderately-built 4L80E which can easily handle the power. Yes, a 4L80E will require some tunnel mods, but likely minor and invisible from inside the car. IIRC on a Gen-2 it only requiring some hammering to make room for the cooling lines and cutting the ears off the transmission case; no cutting or holes in the tunnel. Check the Gen-3 forums on what might be needed. BTW - with an aftermarket converter, the 4L80E weighs only 30 lbs more and looses only 5HP compared to a 4L65E. (The Internet claims that the 4L80E weights much more are due to the craxy 70 lb weight of the stock converter. And a member here dyno'ed that the additional power loss was a bit less than 5HP.)
PerformaBuilt and RPM.
That's who I'm going to use and I'm in Houston with you. I'm a little biased to one, but I'll let you do your homework and figure out which is best for you.
I would go with RPM Transmission for the new set up. I'm a happy customer with the Level 6 T56 Magnum in the 99TA. When my 02 Z28 gets a new transmission it will be an RPM Transmission 4L60e. Excellent customer service too A++
If you keep that car looking that stock with that kind of power.... holy SH-EE-AT.
I like Performabuilt. They'll build you a 60 that will handle your power at the drag strip and honor your warranty. Solid **** right there. I like mine. Probably around 3,600 stall. I'd call Circle D about the converter. They'll talk to you as long as you need, no worries.
Yes, FLT (Finish Line Transmissions) just outside Chicago is still a "go to" shop. The owner Chuck was a founding member of ls1tech, but got burned out after answer a zillion questions here.
We should greatly appreciate that Performabuilt is very active answering questions here and take that into account when selecting a shop.
We offer a variety of 4L60/70 TRANS ranging from heavy duty to extreme off road daily performance and of course the SUPER "BLACK EDITION" have some running this one at over 1000 RWHP in full sized Trucks. Soon to have one put to the test at over 1400 RWHP. NO ONE HAS BROKEN ONE OF THESE YET DUE TO POWER.
The Mods we do are in many cases unique even utilizing clutch sets during Auto shifts where they are not normally applied stock to one unit the does not use the input sprag at all (Still in testing)
Modifications to the 3-4 clutch circuit hydraulically and physically allowing it to hold some crazy power with an insanely quick shift transition.2-3.
And we are always testing new ideas and ways of doing things.
We never stop trying to find a better way, Noting is ever good enough and as I state many of our mods are unique to our builds.
And while I am not always here to see every question We are always just a phone call away . Email or have a cool direct chat on our new website.
You can also watch us actually Building yours and others transmission live on our YouTube channel which is live showing both building work benches daily and we also have done many videos of individuals builds at their request you can find on our Facebook
We have the longest warranty in the business and do not have a bunch of if ands or buts written into it like you see in most.(Yes we DO WARRANTY THEM IN RACE APPLICATIONS) That is what we build them for.
Check out our Facebook you will find lots of great pics and videos along with DYNO test and TRACK runs from out customers and many actual BUILD VIDEOS.
The Mods we do are in many cases unique even utilizing clutch sets during Auto shifts where they are not normally applied stock to one unit the does not use the input sprag at all (Still in testing)
Frank can you tell us more about your units without an input sprag?
Had an RPM basic level 4 in my LT1 car. Flip-flopping between RPM and performabuilt for my current car. RPM offers an additional level or two of modifications and price points. Wish PB would offer a "level" with a billet output without stepping up to the black edition. I've got a triple disk 4000 stall from FTI waiting in my closet lol.
Had an RPM basic level 4 in my LT1 car. Flip-flopping between RPM and performabuilt for my current car. RPM offers an additional level or two of modifications and price points. Wish PB would offer a "level" with a billet output without stepping up to the black edition. I've got a triple disk 4000 stall from FTI waiting in my closet lol.
Its is actually possible to get the billet input without stepping up but you will need to call Alan at the 888 number for pricing on that.
Its is actually possible to get the billet input without stepping up but you will need to call Alan at the 888 number for pricing on that.
I see you guys sell 4l60e, 65e and 70e all for the same price and rated to the same amount of power. What is the difference between these transmissions and what would be pro/cons of choosing one or the other?
Around 1995 GM created the 4L60E (based on the previous 700R4).
Around late 2001 GM upgraded the trans a little and called it the 4L65E; there is no visible difference on the outside. (Compared to a 2-part 300mm 4L60E).
Around 2006 GM added an Input Speed Sensor (ISS) and called it the 4L70E.
Around 2009 GM made some electro-mechanical changes which are incompatible with previous years and kept the 4L70E name.
So basically, there is no major difference. You simply specify if you need ISS or the 2009+ version and a vendor like Performabuilt will build you a unit according to your HP needs (and budget). Their Level-2 exceeds the strength of the 4L70E, regardless of whether they call it a 4L60E or a 4L70E.
GM did create a 4L75E to handle 650 ft/lb, but the high $4200 price (or $3500 for a "re-manufacturered" via Jegs) is more expensive than Level-3 (?) units from sponsors like Performabuilt.
Around 1995 GM created the 4L60E (based on the previous 700R4).
Around late 2001 GM upgraded the trans a little and called it the 4L65E; there is no visible difference on the outside. (Compared to a 2-part 300mm 4L60E).
Around 2006 GM added an Input Speed Sensor (ISS) and called it the 4L70E.
Around 2009 GM made some electro-mechanical changes which are incompatible with previous years and kept the 4L70E name.
So basically, there is no major difference. You simply specify if you need ISS or the 2009+ version and a vendor like Performabuilt will build you a unit according to your HP needs (and budget). Their Level-2 exceeds the strength of the 4L70E, regardless of whether they call it a 4L60E or a 4L70E.
GM did create a 4L75E to handle 650 ft/lb, but the high $4200 price (or $3500 for a "re-manufacturered" via Jegs) is more expensive than Level-3 (?) units from sponsors like Performabuilt.
Ahh that is interesting! I was under the impression they all had the 4l60e and the other models were just beefier variations which is what triggered the question when I looked at their web site and saw they all are capable of withstanding the same HP. So if I was to swap this behind an LS1, 5.3L, 6.0L, LS2 or LS3 I need to have the correct auto trans for it? or will any of them work? I know you mentioned having the ISS for certain years. Also looking at 4L80e.
02-14-2019, 08:23 AM
What Trans To Run And By Who??? 
