89RSTBI

iTrader: (5)

I have the GM part # 12486572 TBI intake for vortec heads and it looks just like GM part # 12496821. The question I have is where do I hook up the brake booster at on this intake. Another thing I have heard the stock throttle/cruise control bracket will not fit, anyone know where to get one that will or at least a part number I can look for? I wasn't sure if this was the right section for this question but since it is a TBI intake figured I would give it a shot

CAMAROSKI

i am looking for the same parts and info.just getting all the parts for 350 vortec with tbi vortec intake

89RSTBI

iTrader: (5)

looks like we may have to figure this one out ourselves and help others when they come ask the same question

89RSTBI

iTrader: (5)

here is a picture of how I have my brake booster hose hooked up. I am not sure if this will work 100% and will not know for sure until later this spring when I get the engine back in. If anyone has any concerns or suggestions let me know

Pin-it_Dad!!

In the middle of a Vortec converstion. I routed the brake booster in a similar fashion. Being a home shop machinst hack with a tig welder I made little slip collars then sliced up the original metal booster tube to get the routing to my preference, then tig'd the joints. dunno how it works yet, cant get the engine to run lean enough to get it out of the driveway.

The throttle cable plate didn't fit up either. Sliced a section out of it, then welded it back together. Seems to work fine.

I have a '88 K3500 BTW. Nothing 'go fast' about it, but we get there.

Where did you park the coolant temp sensor? I had to bush mine up next to the t'stat but the stock EGR hovers over it and sort of jams up the connection. Not sure it is right, but I get temp sensor readings thru the scan tool. Just doesn't look like a very elegant solution though.

89RSTBI

iTrader: (5)

right now I have the temp sensor in the only hole it would fit in, right on the front of the intake directly in front of the thermostat housing. I do not have the engine fully assembled yet and the intake isn't even on the engine as of yet so not sure if I will need to move anything yet or not. I haven't tried to tackle the throttle bracket thing yet but knew there was going to be a problem there as well. I was really hoping someone made one for it but I may have to end up doing some type of fabrication also for it

Pin-it_Dad!!

The horizontal hole that comes out the front looks like the right fit until you try to mount the accessory plate to the front of the engine and heads. It got buried in my application and I could not get the sensor plug onto it.

89RSTBI

iTrader: (5)

Ahh as I said I do not have it on the engine so you are probably correct here. I was just trying to find a place it would fit while it was off the engine and that was the only hole the correct size

Pin-it_Dad!!

consider me the ghost of the pain-in-the-a$$ future. I'm two months ahead of you. If you plan on running the egr system, you'll need a manifold pipe equal to Dorman 598-200, summit racing part number RNB-598-200. It goes from the drivers side manifold to the large diameter hole that is near the #1 cylinder on the manifold. I have pacesetter shorty headers on mine, needed to make a bung for the header tubes. It's a straight thread style, I found that a piece of 3/4" schedule 40 pipe was a good blank to turn it out on a lathe. I also ended up shortening the exhaust manifold end of the crossover tube about an inch and a half to clear the brake booster and air injection piping. A 1/2" flaring tool re-set the end and it bolted up fine.

If you don't know already, Vortec heads use 5/16" bolts; at least my aftermarket heads did. The GMPP manifold has 3/8" casting holes. I don't have any experience w/ domestic engines, so I made some spacer sleeves out of aluminum, and some screwy grade 8 studs that had 5/16" on the bottom half and 3/8" on the top as some of the accessory rails and lift lugs mount on top of the manifold hold-downs in my instance. The sleeves and studs are probably not necessary but I don't know enough to decide otherwise and the lathe was a nice diversion from the aggravation of the revalation.

The serpentine support leg that goes to the stud on the thermostat housing had to be shortened about an inch, the a/c compressor leg stretched the lenght of three 3/8" washers between the bracket and the back of the Harrison a/c compressor that came with the truck.

Like I said before, it's for an '88 K3500 and it's the one and only domestic engine I've ever had my hands on, so I have no idea if it's applicable for your project, but if you get to a stumbling point, you'll have an idea.

89RSTBI

iTrader: (5)

I just realized I have the part number wrong on the intake. It is 12486572 instead of 66572. Not sure how I messed that up but I am guessing everyone knew what part number I was talking about

Pin-it_Dad!!

My comments have been surrounding GM Performance Parts #12496821. I don't know your part number but I do know that there are not a lot of manifolds that have a TBI mount but have the tall trapezoid style intake runners of the Vortec head. That is the reason for spending all the money in the first place, and why I ended up mailing back an Edelbrock manifold.

89RSTBI

iTrader: (5)

yes it looks just like the 12496821 , I just wanted to get my part numbers corrected for future reference if anyone else has these problems, I had the part number correct in the question but in the topic it says 66 instead of 86. the reason I got this intake was because I just didn't like the idea of using a 4 barrel intake with adapter plate and it had the provision for the EGR valve (even though I am in NC). The one thing i noticed on the camaro that may be a little different than your situation (but is still a problem) the bolts for the 305 that was in it had 3/8 holes in the heads and 5/16 for the accessory bracket (exactly opposite than yours was) but hopefully I can just get 5/16 studs and remedy this problem

89RSTBI

iTrader: (5)

looking at this picture I think the temp sensor will be ok for the camaro

Pin-it_Dad!!

definately different than my layout. I'll stop talking now. Don't want to lead astray. Great news on the 5/16 top and bottom studs. I have a few studs that are metric on top of the nut, and 3/8 SAE below. Seems like if it bolts to the block, it's sae, everything else is metric. For example, the air pump to accessory plate is sae, the bolts that go thru the acessory plate into screw holes on the air pump are metric.

I also leaned that the 88 350 for cars had a roller cam at the factory, whereas the truck engines did not. The GMPP catalog also had some clues in the footnotes of the intake manifold section on how and what to hook up to it, so you might look there too if you are trying to solve some puzzles. I downloaded a PDF from the 'net and studied for a while.

89RSTBI

iTrader: (5)

I find everything you have said to be really helpful. Even though the layout may be a little different on the front it still pertains to the same intake and all information may be helpful in the future

irishhockey34

iTrader: (12)

I ditched my PCV value for a breather and ran the booster line off of the port that the PCV valve was plugged into.

89RSTBI

iTrader: (5)

wow I wouldn't think that would create enough suction to make the booster work properly. Do you have any braking problems?

jbucago

what kind of advice would you guys give a guy guy that is just starting out... who has a stock 305 tbi...

i mean i wanna do the vortec build.. on a 305... ive read all the stickies and what not .. im just... well i dont know.. hazy on what year the heads and cam come from... and tuning.... well i guess ima go read that stuff again...

89RSTBI

iTrader: (5)

ok you are going to use a Vortec 305 or the car has a 305 in it now? If you use Vortec heads you will need a vortec intake. You can use a 4 barrel Vortec intake with adapter for TBI or you can get a GM intake like the one I am talking about in this thread and not use an adapter. The stock intake that is on the 305 that came with the camaro's will not fit on Vortec heads

mddavis

I'm new to this and I know these are old post but is anyone currently working on a 12496821 intake? Or does anyone still have pictures of the various hook ups- temp sensor, bracket positions, etc. I have one on and am about ready to put the motor in but am lost in a couple of places.

KolostomyBag

This is going on 2 years now I know, but was curious if you got project done and what luck you had with this intake? What changes did you end up making? Thanks for your time