IROCtheZ28

To the point. Can I use a complete 86 intake assembly or 89 intake & above for my stock '88 305 block?

After much frustration with the Torx bolts, I have removed my intake manifold finally and went looking in Ebay, Craigslist etc for another decent intake manifold. Knowing what I pay for is what I get, it seems I cannot locate an '88 manifold to get my vehicle running again but willing to try alternative routes sticking to the TPI setup. I also familiarized myself with the cold start injector, MAF vs Speed Density, maybe some more but I'm not quite sure yet.

I am still learning about this particular setup GM did. I could use a link or some basic info as to what year intakes I can simply swap with and does it matter if it came from a 350? Once it runs satisfactory, I'll consider a 383 crate longblock in the future just for the noise.

Reason for the original intake removal: Thermostat bolt hole stripped beyond repair. Saving it for a helicoil job much later.

I know parts are harder to come by and I'd like some feedback. Thanks in advance.

IROCtheZ28

Extra research done here states 305 to 350 intakes are interchangeable. This is a good start.

http://tpiparts.net/305_tpi_to_350_tpi_conversion

Rice Killer87

They use the same intake on the 305's and 350's...just the injectors are different.

ws6transam

I've got a TPI intake manifold laying around the basement. I don't remember which year it is, but I think iit's from a 1985 application. It'll work on any engine or cylinder head combination. About the only thing I think you might need to do is enlongate the center holes to mate with revised bolt hole angles. That is what TPIS does with their Minirams. It's what I did with an old Edelbrock Torquer intake which I adapted to centerbolt 1988 heads once.

If you want it, PM me with an offer.

Tex95Z

in short yes you can. However, 4 bolt holes in the center of the intake will need to be modified as the angle is different on the 87 and up heads. hope this helps. P.S. I just used an 86 intake on a 95 350 truck engine.

IROCtheZ28

Thanks for the replies. Just fixed my laptop today and ready to do some more research. Just picking on your brains here...for my '88 305 TPI setup.

The '86 intake (1st pic) & the '87 intake (2nd pic) are totally identical to me. I still feel uncomfortable about planting an '89 305 intake thats here locally and not knowing what problems I'll encounter. The elongation of the center intake bolt holes, I guess I will I have to trust in a machine shop soon? Need elongation details. Gotta love GM in all their wisdom.

ws6transam

Just Helicoil the hole, man! It's not *that* expensive! Spring time is just around the corner! Get it running, mate!

However, if you can find the 1989 intake, you'll be fine for putting it on a 1988 engine. The intakes are the same for those years.

Model Year 1985 & 1986 are the only odd TPI intakes out there as they are designed for pre-1987 cylinder heads.

In 1987 the bolt hole pattern changed and it stayed the same until 1992.

IROCtheZ28

Spring is around the corner they say but we're gonna get hit with significant snow here in the Northeast very soon. Anyways, I would much rather have my ruined '88 intake as a paperweight since I had so much trouble removing the broken thermostat bolt. Got a HeliCoil set on the way.

WS6, thanks for clearing up my issue with pre '87 designs. Really appreciate that! That will also save me some money in future projects as well.

Question: Where to find new Torx intake bolts? Them 20+ year old bolts extremely tough to remove! (Yes, I soaked them with penetrant prior to removal) I definitely want to find new ones since I was nearly stripping them at the Torx tool bit. I'm guessing through the dealership or ARP? I've seen chromed out ones but I like the flat black stocker look. Another observation. Old bolts also seemed to accept two different Torx sizes with a lil but of play found. I'd like the exact size Torx bit size to make sure I do not strip down the new ones. I have a good torque wrench and Loctite ThreadLocker on the side for the new bolts. Maybe a different non Torx bolt suggested?

chevelle600

about the bolts, if you're just scared about stripping them out, i just slotted the heads with my dremel and used a flathead screwdriver to get them out. im not really caring about looks.... yet.

IROCtheZ28

Just out of curiousity, would a 92 TPI unit fit onto '88 305 heads?

http://cgi.ebay.com/ebaymotors/_Car-...1%7C240%3A1318

I seen this on Ebay and was wondering if...the injectors would have to swapped conform to '88 ECM parameters and what else am I missing? Prom burning as well? I have a Hypertech Stage Street Runner Chip #128841 on the side for a future install afterwards.

Goin' back to garage duty... cleaning original intake runners and '89 manifold.

ws6transam

Nope, there isn't any reason why you couldn't run that on your '88 car. About the only thing I see that might be an issue would be if your 1988 used the cold-start injector or not. If your 1988 ECM needs cold start injection, you would need to accomodate for that, by using your original fuel rail, or else upgrade to a #7730 speed-density ECM and harness.

IROCtheZ28

Performed a Search. I'm observing an obvious and glaring difference now. I may reconsider installing the '89 intake therefore several questions arise; 1-Am I correct to assume that I won't need the cold start injector? Looks like I'll look into elongating bolt holes on an earlier intake offered. 2-Need details on where exactly needs elongation, do I need a find a template? 3-Do I need to find an 89 Prom with no VATS? Valid newbie midnight questions.

Digging deeper into a 2006 post.
[89 was the changeover years for alot of stuff]

88 had MAF, cold start inj., no VATS
89 had MAF , no cold start Inj. and VATS
90 had SD, no cold start inj., and VATS

if you want to use a cold start inj., use a 88 PROM
so to do away with the cold start inj., you need a 89 PROM with VATS removed

(Left) 85-88 Intake (Right) 89-92 Intake
Note: (Left) Intake has a coolant temp(a) and a cold start sensor (b) for the ninth injector.
(Right) only has the coolant temp sensor (a) for cold start and coolant temp for the
computer.

Point me in the right direction. It's late at night and getting confused but would appreciate the feedback.