727 Transmission help- No reverse

I bought a rebuilt SB 727 trans with a manual valve body some time ago. I finally got my street rod running with this trans. I did a test run around the block. I have NO REVERSE. Park, nuetral, and 1,2 & 3 all work. I can't find the guy who did the rebuild. I disconnected my shift linkage and put the trans in reverse with the trans lever and still no reverse. I pulled the pan and the valve body. Everything looks like new. It appears to have a transgo-2 shift kit which I found out is not a full manual shift as it still has the kick down\ throttle shaft. Due to a design error I have no access for connecting up the kick down linkage to the carburetor. The low\reverse band is all ok and the adjustment correct. With the valve body off I blew 30 psi air into the trans casing ports and the rear and front servos actuate. Also I hear a thud when applying 30 psi to the front and rear clutch ports.
What I really want is a full manual (reverse shift pattern) with 1st gear braking. But before spending any more money I want to get the reverse issue fixed.
1) Could not connecting the kick down/throttle linkage cause no reverse??
2) Can I modify this valve body and make it full manual, with reverse shift pattern and 1st gear braking?
Don
"5.7 Hemi Street Rod"

TP linkage won't affect Reverse.
You can't modify a stock VB to manual reverse with LBA from a kit.

Since the servos air check OK the problem has to be in the VB, possibly in the manual valve or a missing check ball. If the large check ball is omitted when reassembling the VB there will be no Reverse.

I opened the valve body and have all the balls. I do not have a line pressure limit ball and spring. I assumed this trans does not use it. The transgo-2 instructions say to drill a hole next to this spring and ball ONLY if the trans has one. No 3/16 holes was drilled.
1) What determines if my trans needs that spring & ball.
Don

Use a rubber tipped blow gun recheck the rear band apply servo. You will need to hold the tip tightly in the hole. Give it a blast of air so it applies then let go other trigger while still keeping the tip pressed into the hole.

The piston should stay apllied for some time.

If the piston retacts as soon as the air feed is cut off you have a seal problem in the servo piston.

I'm not sure by your description if you have a manual valve body or a TF-2 modified VB. Are you certain it is not an aftermarket manual body with a trans brake? If it is, many of those brake designs require you to apply the brake while the lever is in neutral to get reverse.

Definitly don't have a trans brake. It has a transgo level 2 shift kit modifiocation. It's a completely fresh rebuild transmission. It must be somethink simple, but I'm not a transmission guy. Just been reading the manual and Munroe's torqueflite book. I'm looking at buying a complete new manual valve body, but I don't want to spend $250 and still have no reverse.
Don

If you air check it as wild bill said to check and all the servo and clutches work, it is the valve body
Thad