View Full Version : renix to ho
11-12-2009, 02:07 PM
anyone know if a ho intake AND exhaust will bolt up to renix head?
11-12-2009, 07:56 PM
with modifications of a tps sensor i do beleive
11-12-2009, 08:57 PM
yes it will bolt up, all jeep parts pre 96 are the same ho or renix BUT there is different tps sensor, have to extend your o2 sensor, change your throttle cable cause the throttle bodys on the 91+ are different, they dont go down beside the intake and back up and its on the other side, if you can get all the brackets with the HO intake and exhaust you will be able to figure it out no problem, pretty simple swap, tony (DH-4-EVER) should pipe up in this thread as he did a stroker in his xj but has 91+ injection and electrical system in his jeep,
11-12-2009, 11:43 PM
You internet mechanics are all the same 
Get some real world knowledge and you would know . . . the Renix and the Chrysler injected cyl heads are very different, same basic shape and size and share a bunch of common bolt locations but that is where the similarity ends.
The 87-90 manifolds and the 91 and up have the same bolt pattern to bolt it to the head but the intake port placement shape and size are completely different the 91 up port is much higher in the head and is smaller and more square than the 87-90 design resulting in much better port velocity which means better performance. So if you actually try to run a 91 up manifold on the 87-90 head it will bolt on but you will have such little gasket mating surface on the bottom side of the ports you will have nothing but intake leak nightmares.
If you are looking for a performance upgrade, the "HO" intake manifold will not do much in itself, the "HO" was a better performing engine than the Renix because of the total package. New head design, cam profile change, better functioning ECU, and more reliable electronics, it was all combined to make a better 4.0
11-13-2009, 09:00 AM
Thanks nutbar, but it's not a upgrade :) my 98's oil pump went an I got a 88 motor to swap in , I was just looking to see if I need to swap the heads (which I see I do) all fun !
11-15-2009, 01:12 PM
It's started! ...I lucked out (ish) and got a 89 larado longblock.
It's in great shape but I cant use the head in my 98xj.
Got a motor, engine stand and hoist
I wish I had a 258crank and rods handy (or a budget for one)
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