Can anyone tell me what size and of how many I need to bolt up a set of runners onto the intake manifold.

Parts Dist.INC. could only tell me that there was (2) M8x1.25 - 39.5 & (4) M8x1.25 - 54. that were required for the 89 'F' engine for the entire car. That's only 6 torx head bolts. I told the guy that there was 6 bolts on each side, but he couldn't find anything else in his computer.

I thought there was three different sizes for each side of the runners at the intake manifold, or am I wrong in this and the sizes above are for just one side, making it just two different sizes for each side.

Thanks for any help.


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92 Camaro RS
89 Iroc-Z Convertible

 

Yes there are three different sizes. They are all M8's with different lengths.

There are 4 bolts holding the top of the runner to the plenum. They are all the same size. I used M8 x 1 1/8" long threads. There are 6 on the bottom. 2 rather long ones, and I can't remember off hand, now many of each of the others. It gets werid since one bolt for each side goes in from underneath. There are both a M8 x 1 1/8" and M8 x 1 3/8".

If you don't trust anyone, take the something to measure the depth of each of the thread holes and add the thickness of the runner mounting flange + gasket.

Mark.
PS. I did check my GM manual and it did not list the sizes.

 

I just put my runners on a couple days of go and I can tell you that there's more than 3 different sizes. Where the runners bolt to the intake there's 4 long bolts (2 on each side) that go in the middle of each section. There are two that go in on the back side that are shorter than the long ones but longer than the rest. That makes 4 out of 6 bolts on one side. On the drivers side, the remaining two bolts are the same size as the bolts that bolt the runner to the plenum. On the passenger side one of these bolts are the same as the ones I just mention but the very front bolt (at least on my '86) is not a torx bolt but rather a bolt with a stud sticking out which is used for the alternator bracket. I imagine if you have the serpentine setup then you probably don't have this one. As for the bolts that bolt the runners to the plenum, all the bolts are the same length. Again, on my 86, the top center bolt on the drivers side is a bolt with a big spike coming out of it which a little plastic "loom" slips onto (for the 3 cables coming off the cable brackets on the plenum). Sorry I can't help you out with sizes but at least you know which ones go where.

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1986 Trans AM
355 TPI
4 Wheel Disc Brakes
9 bolt Borg Warner Rear (2.77's....oh joy) :P
6" rods, approx. 9.7:1 Compression, Stock TPI (soon to be ported), 24#/hr LTI injectors (cleaned and flowmatched by Cruizin Performance), Hedman Shorty Headers, 3" exhaust with 80 series flowmaster, SBC 993 heads completely redone and modified for 1.6 RR, 1.52 RR (for now), Comp Cams XE262-14 TPI Cam, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Ignition, Hypertech 53,000 volt coil.

Track times to come.

[This message has been edited by 86TpiTransAm (edited November 17, 2001).]