4.1 rear for TR-6

[gdk@thumper.bellcore.com (Gabor Kiss)]

I found out that The Roadster Factory had a 4.1 crown wheel and pinion
but that they wanted $470 !! in addition to the $675 for the normal
rebuild. Someone sent a reply to my posting that I could accomplish the
same thing by simply using a smaller tire, and get better handling
besides. Has anyone had experience with this? What size tire should
I get? Naturally my speedometer will read wrong; do I have to live
with that or is there an adjustment somewhere?