I have a 1987 Trans Am 5.7 TPI motor. Here's the number on the heads: 14101083

I just figured they were L98 style plugs. AFR tells me that L98 style plugs are angled. Mine appear to be straight. So what's going on here?

 

The vette L98 heads have angles plugs. You have an iron headed L98 like came in every other f-car, which has straight plugs.

But IIRC, you'll get the best plug clearance with heads with the L98 style angled plugs vs. regular angled. Straight plugs obviously suck.

 

I've never noticed any problems with my straight plugs. What's the problem with straight plugs in a thirdgen?

I've never seen angled plugs to compare.

 

Straight plugs put the spark plugs in bad spots with thirdgen headers. Makes getting a socket on some of them impossible, or pretty damn close. Angled plugs put the plugs in a much easier spot to get to.

 

which would be better on TES headers, angle or straight?

 

Angled plugs look like gravy with SLP headers IIRC.

With TES, because of the dumb routing on the passenger side, i have no idea how it would work. But the driver's side should still be easer.

 

I had aluminum L98's with TES headers and the plugs weren't horrible to get to. Not a walk in the park though.
You have to get some from underneath with a box end wrench, still went fast though. I didn't have to make any special tools, and this was with reg length AC plugs.
My AFR 190s have L98 angle plug location also and about the same as above.

 

Thanx for the info Ed and Fake.

Could you guys help me decide which headers I should buy then for the AFR190's L98 angled plugs. Ive read some threads about 1 3/4 might be too big for some applications and 1 5/8 might be too small for others. Im pretty much building my car to have monster torque at the low end. Ill be using the ZZ9 cam with the heads.

 

If i was buying new headers for a 350, i wouldnt even consider 1 5/8 as an option myself. Any slight loss in extreme low end torque with 1 3/4 is far outweighed by their gains across the entire useable powerband

 

Agreed, forget the 1 5/8.
1 3/4 won't be too big for your setup.
Chances are, fast won't be fast enough and someday you'd be looking to go with 1 3/4 anyways, I wish I would have started there.
As far as fit, I've also heard the the SLP headers are a great fit with L98 angle plug heads. Forget about TES; besides the small primaries and odd pipe routing, they have the primary/flange welds inside the primaries and the a.i.r. tubes stick way into the tubes also, not good for power. The opening is really only like 1 1/2 inch with the weld there. plus the the tubes are pushed in to make room for the header bolts wich also sucks.
So for shorties I'd look to the SLP 1 3/4.
If you really wanted 1 5/8, check out MAC's website, they have a nice set that could be an alternative to SLP's.
For your stated goals, long tubes aren't the choice.
good luck