ive got a d300 in my 88 yj and im redoing the dash.im eliminating the speedo and woundering what people have used to plug the hole in the case where the cable hooks to.also i have a vss for my howell tbi on the 258 and i have read of some people not running this.can i do this or just leave it.ive run it for the last 2 years or so with it. i got mixed answers when i did a search.

You can run the tbi without the vss, it will just think your in neutral at all times. The addition of the vss was to meet compliance for smog.

For the speedo hole, could you just leave the adapter in the hole without the cable hooked up?

will it make any differance in the way it performs when the engine is under load, is there any ill effects to running it without the vss with an auto trans.

Not that I have ever seen or felt, I have ran 2 setups without vss, one was a tbi kit installed on a 383, and now a tbi installed on the 4.2L. I have also owned several stock Tbi engines in the past, throttle response is similar in all setups.

If I remember correctly the exact reason they use the vss is so that over 35mph(roughly) it cuts the fuel slightly to improve emissions while at cruising speeds.

ok cool,jeep is getting green stickered here in a couple weeks so smog is not a worry.