converting 87 manifold to 89+.some prob.need oppinion
 

ok.here is my problem.i'm trying to mate the 89+ upper intake to my 87 lower.i'm hoping some of you have done the same and can tell me what you did.of the 4 studs and 2 bolts,1 stud does not line up.its about a 1/4" off...i figuere i have 3 options...it looks like i might be able to redrill the hole in the flange of the [upper] manifold.the thing is,in order to fit a nut on there,i would have to grind out a bunch of material on the sidewall of the manifold...pretty hairy,its not that thick.2nd option.have the local welding shop weld on a extension piece and move the stud over...but they want 120 bucks to do it!!!so,maybe i should try and find a 89+lower intake and use it instead...but,they seem pretty hard to find...[anybody got one?],not to mention it could take a while to find it.any ideas here?oppinions?something i have not thought off?thanks a lot!

They don't intermatch. Same thing when I tried to do that. The only hope is to get the lower as well. Or go back to the series 4 upper. The TB wont fit between years either...weird stuff.

thats odd, i've been wanting to do that mod, and the only problem i heard about was some kind of notch that had to be ground off... I'd look for a lower intake, try www.car-part.com, i noticed they had a lower intake b4. Good luck, let us know how it turns out!


~Jesse

hmm....thanks for the link,skibum..looks like a couple of places i can call tomorrow.
fc3s:are you sure about the tb?i looked at mine,and i am pretty sure that it i can make it work..i will have to grind of a pretty large spot,but to the best of my knowlage the "bump"is non-functional....not a 100% sure till i go at it with the grinder,thou.a few vacum passages are slightly different,but once again,i think it will work....will the 89+lower bolt to the block fine?hmmm.anybody else with info on this?thanks guys!
david

I could be wrong, but I seem to recall it being that way. The 89+ TB wound't fit the 87 intake and the other way as well. The bolt pattern was different. We never did confirm if the lower would bolt up to the block. I just went back to the original one.

well,my 87 tb fits just fine on the 89 intake,as far as boltpattern goes.the only problem is a "portrusion"on the bottom that interferes with the upper intake,as all the runners are bigger.but,like i sayd,i think i can just grind it off.there is some small diferences in the vacumm routing on the black "gasket/whatever/spacer plate"thinggy,but,i think nothing that will cause poblems.
still hoping to hear from some people that have done this.thanks
david:rolleyes:

Yes, the 86-88 TB WILL fit onto the 89 intake plenum with some surgery to the nib on the bottom.

Yes, you need the lower intake manifold from an 89.

PaulC

I read a web page of someone that had done that swap (we are talking N/A right?). The EGR valve had to be removed for clearance and some electrical connection difference with the BAC valve. Have you found that to be true?

Keep us posed on your progress and what kind performance improvement does it bring.

I have considered the swap myself but after reading others experiences it didn't sound like it was worth it.

Yeah, this has been bandied around quite a bit and though a few people have gotten it to work, there was only one person kind enough to document his entire process. For a while though, Jeff's page was down for the longest time...

Until now that is. Jeff's page is back up on a new server and all his helpful information is available. Here is the direct link to the 89 on 86 intake swap for all you to enjoy.

http://216.222.232.75/Mymods/89_intake.htm

The link doesn't seem to be working, at least for me anyway... Thanks for posting though 256qam, thats probably exactly what we were looking for :)


~Jesse

yeah,i'm not havingany luck with that link either....i have tracked down a 89 lower,so i will try that[once i get my hands on it].i'm using a t2 center housing,w/o egr valve,so i wont have to adress that issue.....i'll keep you posted.