B&M Hammer help

Lay underneath the car and you'll see the shifter cable. It connects to the transmission. Well there are I believe 3 grooves where the cable can be seated into. Losen the bolt and move it into another grove. I'm not sure if the car has to be in nuetral or not so here are the directions just in case.
http://www.bmracing.com/media/products/pdf/5.pdf

Hope this helps

I would go with a process of elimination and determine if the problem is with the shifter or the transmission.

Jack the car up and place the shifter in neutral (since this is where you seem to be having a problem). Disconnect the shifter cable from the linkage at the transmission and check to see if the the linkage in neutral at the tranmission.

You should be able to manually grab the linkage and push it forward 2 click (R & P). Then I would manually move it back and count out the clicks from the park position

1st click Reverse
2nd Click Neutral
3rd click OD
4th click D
5th click 1

If you can manually move it into all gears I would venture to say the problem is with the shifter. But to confirm, if you have a friend that can help by sitting in the car and stepping on the brake pedal, you could manually work the shift linkage with the car running and make sure that once you move it into the reverse position the tires spin backwards. Reapply the brakes and move the linakge into the Neutral position release the brake and ensure the tires dont rotate.

I had a similar problem when I installed by new valvebody. When I installed it, I place the shift linkage (inside the pan) in the wrong grove on the valvebody and could never get it into 1st. If the previous owner installed a shift kit of valvebody this may be the issue. If you can not manually get the shift linkage into all gears, this maybe something to look into. It will require dropping the pan to check.

Good Luck