What are available? I already have a phase II block w/ ported/polished DOHC rebuilt heads. Can I convert my 5-speed into a 6-speed or can I just change the 5th gear to a taller ratio for better highway cruising? Thoughts? My transmissions 3rd gear syncro is on its way out and the shift lever linkage in the transmission needs rebuilt, may as well get er done while the tranny's out. 229k miles.

 

get the jdm RA's hella strong i dunno much about them thoe, but there super stong i know..

 

It's not possible to convert the 5MT to a 6MT, but it should be possible to change your top gear. It is possible to swap in a 6MT and corresponding rear differential, but I'm not certain how much taller 6th is than your current 5th.

http://gearboxtech.com can help you out...and don't be fooled, RA gears are not that strong...