[wwilder9]

Originally Posted by 165th

Brewster, here's a pic that may be helpful. Note the cylinder numbers are stamped on each plug wire.

Hey Brian,
I was the guy holding the phone with the wire numbers wrote down on it, What I had on the phone that you guys gave me (from another car) compairing with the numbers on the wires above, we had the 3 and 5 switched, I think that was your problem.

[bird72]

Looking for 71 HO intake & X-over if any HO people like trip over one walking in the woods or anything

[PureSD]

Pm sent

[Brewster]

Originally Posted by wwilder9

Hey Brian,
I was the guy holding the phone with the wire numbers wrote down on it, What I had on the phone that you guys gave me (from another car) compairing with the numbers on the wires above, we had the 3 and 5 switched, I think that was your problem.

Okay, that makes sense and a good possibility. Will check it out this weekend and post the result. Sure gets frustrating at times.

[alloy indian]

Not really the place for this but they don't speak of ebay cars on the 67-69 tech so. Did anyone else see the one of eight trans am verts on ebay with a non original ram4 engine! Looks pretty sweet! seems legit D80 code and PHS.

[A Schab]

It's a clone.

[alloy indian]

I know but someone went to a lot of trouble to make it believable. It needs the air let out of the rear shocks though! I hate it when they leave a 69 so high in the rear the rake to the back makes them look like there going a hundred miles an hour siting still!.

[Alvin]

Originally Posted by bird72

Looking for 71 HO intake & X-over if any HO people like trip over one walking in the woods or anything

Did you notice Bart has '72 HO intake part listed in FS section?

[bird72]

So are 72 and 71 crossovers not interchangeable? Will repro work on 71? And another puzzle: some 197 heads are drilled for 2 end exhaust bolts and some only one? what I deduce from ebay ads. I just got set that have one hole drilled, and Ram Air Ent manifolds are cast for two bolts, so I should have shop drill end hole when do heads I assume (?).

[njsteve]

71 and 72 crossovers are different due to the exhaust riser opening shape on the 1972 heads. Major exhaust leak if you use the wrong one.

[bird72]

That is what I thought Steve, thanks. Do you know anything on the end bolt situation? Should I concern on missing bolts or go with 3... (?) or drill & tap?

[rexs73gto]

You can use both just by installing a thin piece of metal behind the cross over at the port on the head to fill the difference in the gap that doesn't cover it. It's had to be done on a lot of late model heads when changing the intakes . It works fine & if you paint it you can't tell it's there.

[PAUL K]

Most of the reproduction exhaust crossovers are designed to work with either 197 or 7F6 heads.

[1971WARBIRD]

Originally Posted by bird72

That is what I thought Steve, thanks. Do you know anything on the end bolt situation? Should I concern on missing bolts or go with 3... (?) or drill & tap?

i'll just say I drilled and tapped mine. I liked the idea of more bolts holding, just me.

[Judge273]

Good information. 71 is much different in carb, linkage to carb, choke, the look of intake, and exhaust in configuration and part numbers.

Best to find correct piece. Tapping and drilling for nom makes its a molested part....

[Brewster]

Originally Posted by Judge273

Good information. 71 is much different in carb, linkage to carb, choke, the look of intake, and exhaust in configuration and part numbers.

Best to find correct piece. Tapping and drilling for nom makes its a molested part....

Altered might be a better term Mike

[The Boss]

Mike made that sound a little dirty didn't he?

[4birds]

Originally Posted by bird72

So are 72 and 71 crossovers not interchangeable? Will repro work on 71? And another puzzle: some 197 heads are drilled for 2 end exhaust bolts and some only one? what I deduce from ebay ads. I just got set that have one hole drilled, and Ram Air Ent manifolds are cast for two bolts, so I should have shop drill end hole when do heads I assume (?).

Anthony, which heads do you have? If you have 71 HO heads, you must use a 69-71 intake crossover. If you have 72 7F6 heads, you must use the 72 intake crossover, as it is different.

Are you going to use factory GM exhaust manifolds or reproductions? (or headers?) The factory exhaust manifolds on the 71-72 HO's only used 3 bolts to hold them on. That's why the 2 holes are not there in the heads. The reproduction manifolds use 5 bolts (copied from the 73-74 SD) for improved sealing. Therefore you will need to drill and tap the heads if you use the 5 bolt reproductions or headers.

The first picture is of the GM 3 bolts OE manifold. Picture #2 is a R.A.R.E. reproduction round port manifold. Pictures 3 and 4 are 72's. The last picture shows the different long slot for the crossover for 71. (the 71 197 HO heads will match this long slot)

[4birds]

1972 and later gasket on top, up to 1971 gasket on bottom.

[PAUL K]

Originally Posted by 4birds

Anthony, which heads do you have? If you have 71 HO heads, you must use a 69-71 intake crossover. If you have 72 7F6 heads, you must use the 72 intake crossover, as it is different.)

You are correct when using GM parts, however most reproduction crossovers were designed to work with either head.