A few details on my car....

'69 Road Runner
440
TF727 w/reverse manual valve body
2800 stall
3.91 gears

Under 50% throttle, the trans shifts great and I have no issues

However, above 50% throttle, during the 2-3 shift, I get a 300-500 RPM spike before 3rd actually engages

Here's an old video that will give you an idea what I'm talking about:


Fast Forward to 4:33, 5:50 and 8:55

Listen closely to the 2-3 shift and you'll hear the RPM spike....

It feels and sounds just like power shifting a manual trans.

There's no slippage in any gear when I flash it from low RPM's and the spike during the 2-3 shift under hard acceleration seems to be the only issue.

I'm hoping it's just a simple band adjustment, but open to other suggestions before I pull the pan.

 

That's where I would start. Pull the pan and adjust the bands. Drain it into a clean container& re use the fluid.. If the problem is fixed. Use your judgment to change the fluid. could be the clutch pack too ? Could be throttle pressure adjustment on the valve body With a full manual trans ? Check with the guy who built it.. Might be able to get some adjustment figures on B&M web site.. for the throttle pressure screw

 

I adjusted the band last night.

Took about ~3.5 turns to firm, torqued to 72 in/lbs., then went ~2.5 turns out and locked it down.

Noticed a slight difference, but there's still a bit of flair.

Here's another video from today...


Listen closely to the 2-3 shift

Fluid is fresh as it was changed with the tailshaft bushing not too long ago.

Unfortunately, I found out that the guy who built it has passed on

 

Did you remove the orifice plug completely?
If not give that a try.....

 

No, I just tried adjusting the front band since I didn't have to remove the pan.

However, after a bit of research, it seems I may have used the wrong adjustment spec

I went 2.5 turns out, which is apparently the stock spec.

After reading through a few reverse manual valve body installation procedures (I'm not sure which model I have btw), it appears I have it turned out a bit too much



Now, how would I go about identifying what ratio band lever I have?

 

Most are stamped on the lever....