86 chevy crew cab 12 valve swap

[ponjohn]

Subscribing

[84chevyguyid]

I have an allison PCM and a partial harness I thought about using. Just unsure as of yet. Mine is only a 5 speed as well. I just don't like the idea of building a truck, using the a1000, and then hating it because I can't tune it without a trip to allison 20 times until it's right. Or, spend $1800 for Scott's controller. Too much money.

Here is a thread on allison 5 and 6 speeds.

http://www.4btswaps.com/forum/showth...p-guide-thread

I have chatted with howard some over the past year about his system. Sounds like it works great! The down side to it is if a guy wants the tow/haul and tap a shift functions. They arent available with the allison system. The gm system seems to be very complex from what Howard tells me, derating fuel for shifts, locking and unlocking the converter in a variety of situations to help with emissions, shift harshness ect whereas the medium duty allison system is more basic in its function. Will the allison medium duty system work for me? yes it will. Would the tap a shift function be awesome to have? Yes it would. Now you can see my dilemma, which to choose?

[84chevyguyid]

Been learning about what all I need for the allison trans controller and wiring harness. I decided to go the GM route so I can have the tap shift feature and hopefully the tow/haul feature. Been collecting parts to put the harness together. I spent the evening the other night drawing all the components out and making a schematic of the wiring. Got the trans connector, the tcm connector, and the tps. Ordered the terminals for the tcm connector, an obd2 connector with terminals and a nice crimper, should be in a week. I found an 06 shifter handle with the tap shift and tow/haul switches, should be here monday. I am going to adapt it to my stock column, hopefully it wont look to weird when I get done. I still have to round up the wiring and then I should be able to start building the harness. I ordered a tapered reamer for the dodge steering arm so I can bore it out to fit my chevy drag link then I will have the box hooked to the axle. I still need to get the cab blasted and undercoated then I can set it back on the frame for the last time!
I dont know what the handle sticking out on the tcm connector is for, anybody know how this is supposed to work?