81 Corvette said:
Gotta track down a new speedo gear, or at least put a thrid gear RPM=Speed chart on the rear view mirror.
Assuming a 27" tire, 3.55:1 gears, and the lock-up feature of your THM350C is functioning properly, each 500 RPM (
in 3rd gear/lock-up) is equal to 11.4 MPH.
Go to your local vinyl sign/decal shop, and purchase a piece of 'bulk' vinyl, and cut a piece of it to fit onto the glass lense of your tachometer, 'out-board' of the numbers signifying RPM.
Where the tach reads "10", put the number "23" (
MPH); where it reads "15", put the number "35", where it reads "20", put "46", and so-on, for use until you get the correct speedo-gear.
Peel the vinyl decal away, using "
Goo-Gone", or "
Goof-Off" to remove any glue residue on the glass lense:
I did this on my Z28 when I went from 3.42s to 4.11s many-moons ago...
81 Corvette said:
I'm glad I didn't go all the way to 3.73, then again, i sit here and say that without first had knowledge of what it would feel like, but I'm betting traction would be a major issue when i finally get a new motor. Time to start saving for a ZZ4 or ZZ383, and offset trailing arms
With any of the "ZZ"-series motors, traction with 3.73s or deeper would surely be a problem;
my lowly '82 Cross-Fire, with 3.73s, and a 700-R4 with 3.06:1 1st gear, can boil the 255/60R15 BFG TA Radials at-will, but once the tires catch, the L-83 bogs.....
:eyerole
ad
You ain't livin' until you've driven a Cross-Fire.....
;help
I have recorded every gallon of gas into my '82 since I bought it (
May '00), but most of my driving is of the
'casual',
'out-for-the-afternoon/evening' variety, but on 2 occasions (
once with 2.87s, the other with 3.73s), I had the '82 'out' on the open-road.
On a 230+ mile trek, with A/C blowing ice-cubes and the T-tops off at 75+ MPH on the Pa. Turnpike, I got 23.0 MPG (
10 gallons even) with 2.87s:
on a 430+ mile jaunt, over back-roads and country-roads for better than half of it, I got 17.1 MPG with 3.73s.
On neither journey was I making a determined effort to get the best MPG, and in both instances, I was pleasantly surprised.
(
A Cross-Fire does deliver good fuel-mileage, when operating correctly...)
