i have bigger tires and will be going with lower gears.i have a 88 iroc. i am going to have to get the kit that uses vacuum instead of electric.so do i go with a programable speedo?

 

I'm unsure of what you're asking. An 88 IROC would have a cable-driven speedo. To make it read correctly, you may have to swap out the drive and/or driven gears. Search for a calculator to establish your needs.

JamesC

 

i forgot to mention i am putting in a carb and doing away with the computer.i was looking at autometer and they say you just have to program it every time you change gears or tires.is this correct?

 

My 85 IROC (mechanical speedo like yours) has a transplanted, carbed 350 and the computer has been eliminated. These things have nothing to do with the stock speedo. Sorry, I have no experience with Autometer, but I suspect this guage won't work with a mechancial set-up such as yours.

JamesC

 

thanks jamesc i guess thats for non cable trans

 

yeah as stated you have to change the drive and driven gears in the tailhousing of the transmission to get your speedo right again. here is the one i used. Speedo calculator

 

thanks,i was afraid of that,the so called mechenics in this area do not have a clue on how to do it,i have been to every one

 

https://www.thirdgen.org/speedogear

JamesC

 

thanks,so if i get my ratios right i have to keep buying the same size tires for it to be accuarate.i have 29 inch tires with 273s.will be putting in 342s maybe with the tall tires and lower gears it won't be too far off.stock tires were215-65-15 i have 255-70-15