clutch
 

I have a 67 4 speed 289 hi po.The clutch is starting to slip. The linkage is adjusted all the way out. Question is, what size and type of clutch and pressure plate would be the best to put back in? I do like to "burn rubber". Thanks.

I'll leave the size issue to the vendor of the clutch. If they cannot help you get the right part you need a different vendor. On a clutch job you should replace the clutch disk, pressure plate, throw-out bearing and the pilot bearing (or bushing). You should also have the flywheel resurfaced. Now for the real reason for this response. Classic mustang clutches are finicky and in general rebuilt parts from auto stores will clatter after a short time. You need to use either genuine ford parts - dealer (I know $$$) or a high quality after market unit like Center Force. Since your asperations include buring rubber - I would go for the center force - modern clutch technology engineered to meet the needs of classic owners (no I never got around to buying stock in the company).