1990 K1500 5.7 TBI, Transmission upgrade options?

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L31MaxExpress

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My vans mileage did not change much going from a 4L60E to a 4L85E. It had better acceleration with a 4L85E than it did with a 4L60E. The 1-2 shift kills the acceleration on a 4L60E. With the 4L85E and 3.73s I still managed nearly 19 mpg average on a 2,200 mile road trip with the 350 turning 2,400 rpm @ 75 mph most of the trip.
 

1990Z71Swede

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I would DIY the 700R4 myself. if you want to control shift points you can get a 4L60E and upgrade to a '7427 pcm. you will need to repin the connectors and add the 4L60E wiring. The other option is an aftermarket controller which you could use on a 4L60E or 4L80E. EBL is an excellent upgrade but will not control a 4L60E.

You can modify the 700R4 to shift at higher RPM but you will need to source the correct shift valves and governor. I usually find it easier to source a complete valve body. I have the 700R4 in my squarebody setup to shift @ ~5500 RPM and the part throttle shifts "hold" the gears longer which is nice.
Alright, If I understand this right, that means I would need an ECM for EBL plus a 7427 PCM to run the 4L60E/4L80E-box, or an aftermarket controller to do what the PCM does, Because the 7427 is not EBL compatible right? That makes the TH700 route more interesting, any suggestion on what gearbox upgrade kit to get?
It needs to handle a 300hp 5.7TBI Z71 3.73 gears K1500 RCSS, that hopefully does not need to rew much higher than stock,(stock TBi heads with valve job and basic cleanup and hardware to play well with a comp 08-300-8 roller) and does not tow anything heavier than a horse trailer.
 
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PlayingWithTBI

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If I understand this right, that means I would need an ECM for EBL plus a 7427 PCM to run the 4L60E/4L80E-box, or an aftermarket controller to do what the PCM does?
The 7427 has pretty much the same tables as the EBL but doesn't do the "Learn VE". Over on Gearhead EFI, Dave w developed some Accel spreadsheets for tuning your VE tables based on either a NBO2 or WBO2 sensor (different spreadsheets). The WBO2 is the better way to go. Then you'll only need 1 PCM.
 

1990Z71Swede

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The 7427 has pretty much the same tables as the EBL but doesn't do the "Learn VE". Over on Gearhead EFI, Dave w developed some Accel spreadsheets for tuning your VE tables based on either a NBO2 or WBO2 sensor (different spreadsheets). The WBO2 is the better way to go. Then you'll only need 1 PCM.
Ok, Can i access the VE tables directly somehow in the 7427 or will I be burning chips?
 

tayto

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I would get a kit from here:

Dana's kits are very complete and he will tailor the kit & separator plate for what you are doing. he has all the upgrades in his kits.
 

1990Z71Swede

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I would get a kit from here:

Dana's kits are very complete and he will tailor the kit & separator plate for what you are doing. he has all the upgrades in his kits.
That was a great link, thanks! And he has kits for 200R´s too, Just as I was starting to abandon that idea and leaning towards a 4L80 in the 67 Camaro. :)
 
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