87350IROC

iTrader: (2)

I installed them on my 87 IROC 350. I did not have the usual problem of steering shaft rub. Well it touched a VERY LITTLE bit when the wheel was turned but after about a day of drive it ground away enough material on the header to make clearence. Installation wasn't bad except some of the bolts were hard to get in because the larger primaries, they wont' go in straight. Its like you have to put all the bolts in and slowly tighten all the bolts together. Both headers dropped in from the top. Some brake lines had to be bent out of the way but that isn't a big deal. The y-pipe hugs the floor pan real nice. In fact i had to wedge a strip of rubber between the cat adapter and floor pan b/c the pipe was rattling against the floor. I am having trouble getting the passenger collector to seal up. I think i'm going to try some different donut gaskets.

Performance wise i am very happy. Much more top end power. I recomend the SLPs, fit is pretty decent and performance is great, and you can't beat stainless steel. I will gladly entertain any questions regarding these headers and installation.

John

Abubaca

iTrader: (3)

I have the SLP 1.75" inchers too.

The steering column just barely clears the primary, now that it's intalled, but I had to unbolt the column at the steering box to get the header in.

....The Y-pipe fit great, but FYI, don't do it without a second set of hands! ...hehe, that was an experience.


....just fired her up tonight, so no performance data yet!

87350IROC

iTrader: (2)

yea, you have to unbolt the column, mine fit too when first installed but when the steering wheel was turned it rubbed a little. No biggie. You won't be disappointed. What cat and catback are you using them with?

Abubaca

iTrader: (3)

I haven't decided what cat yet, hi-flow of course, but I'm probably gonna run the SLP loudmouth.

That should be fun.

IROCZTWENTYGR8

iTrader: (1)

1 3/4" on stock engines?

Abubaca

iTrader: (3)

I've got a ZZ4 cam now, and some other goodies on the way.

I did TONS of research on the primary size issue on this board and a few others and here's what I came up with. All the hypothetical talk seemed to be that 1.75" was too much, and would kill torque down low, but every single person with the 1.75" headers seemed to think that it was such a big improvement, that even if it did lose a little low-end, it was worth it.

....every aftermarket TPI intake will lose a "little" low end too, but that's just part of doing business.

I'm not saying that the 1.75"s don't give up any low end torque, but from what I hear, most of the difference is on paper, and not really an issue day to day.

Marc 85Z28

iTrader: (3)

I went from Edelbrocks TES (all 1 5/8") to SLPs 1 3/4" with no other mods and saw a noticable SOTP difference. Those who said they were too big either never ran them or were comparing LT 1 5/8" vs 1 3/4". Besides, like you said, since you've got an abundance of low end torque, trading some of that for more high rpm power is a good thing.

87350IROC

iTrader: (2)

Lol, stock engine, no really mine isn't anything exotic. ZZ4 cam, lil port work on the 083s, 10:1, lingenfelter base, AS&M runners, ported plenum. I'm also using a catco direct fit cat and edelbrock cat back.

IROCZTWENTYGR8

iTrader: (1)

Ah, your cars aren't exactly stock I see.

ebmiller88

iTrader: (7)

I put the 1 3/4"s on my stock Iroc and noticed a (IMO) huge drop in torque so I swapped my larger shorties for a set of SLP 1 5/8" so we'll see what that does, I think I'll like it better until I have to go larger for the D1SC in the future.

Ed

87350IROC

iTrader: (2)

I noticed a small drop in torque. But well worth it for top end improvment, especially if i go with a more wild setup in the future.

TPI-Formula350-

Very happy with them. I did have a little issue with them leaning against the steering shaft.

91RS5speed

I put the 1 3/4 on my stock headed cam 305 and it made a huge differance. With no loss in power anywere in the powerband. I did demple the header so it would clear the stearing shaft.

MdFormula350

they are ok, wish i didnt have to dent the primary but o well.
the coating is turning brown and looks like rust almost

o well thats what i get for not making things myself... :lala:

Abubaca

iTrader: (3)

....wouldn't that be an issue for whoever coated them? ...unless SLP did it?

MdFormula350

got them from slp, they warranty the coating as far as chipping, falling off, etc..

they dont warranty the luster

z92maroman

Glad to hear u guys all seem to like the SLP's. My exhaust guy is really emphatic about not going w/full lengths, car is lowered n he says will b nuthin but prob's. SLP's r the only 1.75"s I've found. My only concern is will these flow acceptably on a pretty rad. 383 0r even 434, or am i gonna b chokin the s--- outa it? Thx 4 any info, luv this forum, dont post much but talk about an info source!

D's89IROCZ

I am runnign the exact setup you are . Except edlebrock base and runners ( ported and simesed in 4") I can't wait to see what it does . Anyone looking for pics can hit my www . they are on the third page .

Marc 85Z28

iTrader: (3)

There was a 89? Firebird for sale a couple of months ago in the classifieds with these headers and a 3" single system. Car was running 11.09 at around 122-123mph on a N/A 383, with AFR 210s and a healthy roller cam on drag radials.

Regardless, if you're making well over 500HP they might become a restriction, but not as bad as a 1 5/8" shorty.

tamatt27

I'll be gettin' SLP 1 3/4 coated headers and y-pipe and a 3" high-flow cat that'll go in to my 3" Edelbrock cat-back. When I get the LT1 up and runnin'. We'll see how she runs, I'm hoping for good results!