If u go ebay n put 89 cherokee throttle body they have this blue one that is 80mm . Has anybody bought this isit good and does it fit properly it says its universal so that's what wierded me out. And also has anybody bought an ebay header for an 89 cherokee 4.0 six inline . Just want a review on these parts thanks

 

check out strokedjeep.com

80mm is HUGE 65 is even almost to big for the 4.0

 

So what's a good size to bore my oem throttle body.

 

the 63mm tb from stroked jeep on the link posted earlier is nice. i know quite a few people including me run it.

 

i bored my own to 62mm on a metal lathe. Came out perfectly. Just be careful not to go thin..

 

you should do a write up on how to bore a tb, i have the access to a metal lathe but do i bore it all the way through or what?

 

unless you plan on making a new blade/butterfly, you will only be able to open the bottom of the TB (where it tappers) to match the size above the blade. i think it starts at 59 and tapers to 54 if i remember right. so you would be able to do 59mm straight thru (well the bottom anyway) as long as my numbers are right without needing to fab up a new blade

 

It is easy to fab a new butterfly! i did it with tin snips and a dremel tool. hahaha. Came out perfect with nearly no whistle

 

hmm myabe i'll grab a jy tb and give it a shot so if i go all the way through bore it to what mm? its on a 1990 renix sorry if im thread jacking

 

yea, didnt say it was hard to make one, its a circle :-p just another step to do and make sure it doesnt bind

 

I pickup an OEM style header that included expansion bellows for the front and rear cylinders.
Been on my DD for almost a year and no problems yet. Paid 80 bucks and minimal shipping.

Must say that the construction lacked the attention to exhaust port flow dynamics.
Lots of heavy welding beads in the exhaust ports.

 

You really want a basis to start with?
Google up Jeep Speed Racer, it was a 10 build of a 2 door Cherokee into an off road racer.
Be a good base line to start with.