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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: y2k_harley on November 24, 2010, 03:56:36 pm

Title: Anyone running 2.73's with a 700R4???
Post by: y2k_harley on November 24, 2010, 03:56:36 pm
I recently bought an 83 GMC 2wd parts truck with a 305/700r4 and 2.73 gears.  I wanted to swap the 700r4 in to my 86 2wd which also has 2.73's.  My question is if there is any issue with the convertor locking up in overdrive.  I had a 4x4 suburban with this combo (don't ask why I had 2.73's in a 4x4)  and 31" tires and I could never get the thing to lockup in OD.  Later on I want to go to a 3.42 or 3.73 rearend but want to know how much trouble it would be driving with the 2.73's.
Title: Re: Anyone running 2.73's with a 700R4???
Post by: Grim 82 on November 24, 2010, 04:32:27 pm
Sounds more like a lock-up problem. Your torque convertor shouldn't really care what your final drive ratio is.

Title: Re: Anyone running 2.73's with a 700R4???
Post by: ohio hab on November 24, 2010, 04:48:25 pm
Had the same combo originally in my 84 C-10 and had no problems with the convertor locking up. I now have 3.73 gears, also with no problems. Sounds like the previous post said you have another problem.
Title: Re: Anyone running 2.73's with a 700R4???
Post by: y2k_harley on November 24, 2010, 06:11:05 pm
It would lock up on occasion, just wouldn't stay locked up.  I just figured the RPM's were too low (about 1350 or 1400 if I remember correctly).  Most of the time I just ran in drive and the RPM's were around 1900.

 
Title: Re: Anyone running 2.73's with a 700R4???
Post by: Captkaos on November 24, 2010, 11:03:02 pm
My current 87 R10 has a 700R4 and 2.76 gears.  It does fine and it has stock height tires on it.
Title: Re: Anyone running 2.73's with a 700R4???
Post by: square81 on November 25, 2010, 07:43:46 pm
I had the same set up. Works ok but was lazy and rpms were too low. Changed to 3.73 made the world of difference.