Matt--What size engine do you have and what other mods have you done to it? I'm trying to figure out the same thing for the speedo. I really don't want to have to dish out around $300 for a conversion for the speedo. From what I've read 1984 is guarenteed to be mechanical, but I haven't found anything later than that yet. When I find out exactley what the last year was, I'll let you know.

1985 and 1985 have the best overdrive ratios. For the Camaro/Firebird for 1985-86 it was an overdrive of 0.63 There was also a 0.61 overdrive for the 1986 Camaro/Firebird, but it had a first gear of 3.35 That first gear isn't bad compared to some of the S-10's. GM started using using the World Class T-5 as early as 1988, so maybe the World Class and the electronic speedo came out together. Anyway, hope this helps. John


'68 C-10 - 250 with Edelbrock 600cfm 4 barrel, Offy intake, Hedman headers and true duals, HEI, MSD 6A box, relocated gas tank
Soon to have: T-5 tranny