Need some advice with my 86 C20

[Dutch Rutter]

Hey guys,

It has been a while since I tinkered with my 86.

Here is the back story in a nut shell:

Started with an 86 C20 6.2 diesel, TH400 with 14 bolt semi floater 4:10 rear end.

swapped in a rather built 350SBC, 4 bolt main, RV cam, crank, edelbrock aluminum heads, longer push rods, slightly over sized pistons and rings, edelbrock 4 barrel 680 CFM or so on top with edelbrock performer intake manifold.

Also I believe that I changed out the TH400 TQ converter to a gasoline one instead of the diesel, as well as the governor to one from a gasoline trans.

after doing this the truck had all kinds of low end power and ran fast and strong. Great when I was in highschool. now I'm wanting a to make it a DD with towing power while still having it fun to drive.

I just swapped in a Full Floater corporate 14 bolt with 3:73 and the G80 locker that still works.

Now I have noticed that my trans shifts VERY early, 3rd gear starts at 35mph or so and I have no overdrive (to be expected) that I have noticed nor does the trans shift down when I floor it. (maybe vaccume, maybe governer, maybe TQ converter just not sure)

I recently purchased a transgo 1-2 shift kit that I have not yet installed.

what I am wondering, is WTF should I do from here? (for lack of better explanation)

Option 1: Take it to a shop to install the kit and tweak/tune the trans
Option 2: I live by what you guys say and try to do the above step by myself
Option 3: I continue to drive my dumb lil, under powered ford ranger until it blows then I buy something new.

I really don't like Option 3. But I figured I would get opinions from you all since your knowledge base is AMAZING when compared to mine.

Thank you all for the help in advanced, as I am very stuck in this decision.

 

[Dutch Rutter]

Really needing some input.

I'll be pickup up a governor and a new vacuum advanced module this weekend in hopes of it helping as well as making sure the kick down is wired up and adjusted correctly.

Is there anything specifically important that I need to keep in mind when buying these parts?

 

[foamypirate]

Really needing some input.

I'll be pickup up a governor and a new vacuum advanced module this weekend in hopes of it helping as well as making sure the kick down is wired up and adjusted correctly.

Is there anything specifically important that I need to keep in mind when buying these parts?

You may have to play around with the governor weights and springs to get the shift points where you want. There should be guides online. I've never done it first hand, so can't really tell you what does what as far as that goes.

Sounds like you are on the right track with the kickdown by checking the wiring and verifying you have the switch present on the gas pedal or carb.

 

[CSFJ]

Have you gone through all the th400 threads in the trans forum? The reason I ask, is that If I remember correctly, the 400 doesn't have a kick down cable? Not certain, I do recall that there was something that the th350 had that wasn't on the 400. I think you're on the right track to start with the shift module, though. I know I have read some things here and there on the threads in that forum that may be of use to you. Not really an auto trans guy myself, probably need to hear from a couple of the others here to get a better answer.

 

[Dutch Rutter]

Thanks for the replies guys.

I do remember that it does have the switch by the gas pedal. however I never knew what it was for until I started searching on here. and found some really good information about near the same issue. My 400 does have an electrical something or other on the Passenger side. I'm also not 100% sure if that is for the kick down or just what. I do know that I have never adjusted the switch. If I cant get this figured out I may end up buying a new trans or doing a swap to a 4 speed. Or just buy a running K20 to swap my motor into.

This post is what I figure I'll follow in troubleshooting. http://www.gmsquarebody.com/forum/showthread.php?t=1107
I'll be sure to post back what I find after this weekend.

 

[CSFJ]

Yeah, that's on e of the threads I was thinking of. I had forgotten about the electric kickdown too.

 

[Dutch Rutter]

I have been chasing my tail on trying to make this thing more daily drive able and a weekend tow rig. but I feel as though I'm about there I just have to get these shift points ironed out. Every time I think about dumping a large amount of money (like getting a new trans) into it I wish it was a 4x4.