So question, my dash on my 1991 RS 305 isnt working, the tach is all the way at the end and when its warm and in drive shows it idling at 6k but not actually high idling. My oil pressure guage will show just above red when cold and then 0 when warm, my gas guage is always reading full as well. Is this a problem with the cluster? The guy i bought it from had the intake manifold replaced and said it started after that, he believed the distributor was on backwards... does this sound possible?

 

No , the distributor is not on "backwards" , whatever that even means ....

The Tach on our cars is notorious for having problems just as you describe , a search here will find many threads on it . If all the other lights and such on the dash work my guess would be that the tach has the smoked resistor problem , the oil gauge sender may not be hooked up or it could have a dirty or loose connection to it's wire , and the fuel gauge sending unit could be open circuited (open = way past full and grounded = empty) .

 

Given the amplitude of ridiculousness of that statement I deduce that neither the previous owner, nor possibly yourself are capable of correcting these (multiple, unrelated) deficiencies and I strongly encourage you have a competent automotive electrical technician intervene on your behalf.

GD