I just got a 99 gsr tranny and am putting a 4.77 final drive in it. I was thinking about putting an LS 5th in for the freeway but wasn't sure if that would be necessary.

 

Necessary for what?

Do you do a lot of highway driving?

 

i do a fair amount of freeway driving, this is my only vehicle. so the tranny is being mated to an ITR in a crx and i'm just wondering with the gsr trans with a 4.77 final, around what RPM I'd be at at 80 MPH

 

http://www.fatboyraceworks.com/gears/

have fun

 

Depends on what you feel ok with. I daily drive my 96 Z6 hatch with MFactor gear set. 1.000 5th and 4.250 FD. I'm at 5k +/-100'ish at 80mph. Did two 8 hour round trips to Nashville in a weeks time, then a trip to DC and Baltimore less than a month later, then a 95mph 2 hour round trip about two weeks ago and everything is holding up fine other than my ISB (which I didn't replace when I put the gear set in).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">Depends on what you feel ok with. I daily drive my 96 Z6 hatch with MFactor gear set. 1.000 5th and 4.250 FD. I'm at 5k +/-100'ish at 80mph. Did two 8 hour round trips to Nashville in a weeks time, then a trip to DC and Baltimore less than a month later, then a 95mph 2 hour round trip about two weeks ago and everything is holding up fine other than my ISB (which I didn't replace when I put the gear set in).</TD></TR></TABLE>

It might be because I'm drunk but I'm not familiar with the acronym ISB

 

Input shaft bearing.