What msd tach adapter to buy

[Ramcharger90]

Which tach adapter do we need to use for our rangers? Im using a mustang A9L computer and engine harness. I noticed quite a bit of different options. I want too use my factory cluster as much as possible.

 

[Ramcharger90]

Im guessing I wont need one. I had the cluster from my wrecked 89 stx apart before for "research" purposes I didn't see any pin or anything that said 8 cyl like @1mean02hd said in a almost 10 year old thread. I couldn't find any pics or definitive answers on this.