Finially finished putting these things in. It was going very well until I figured out that the i-pipe was welded to the y-pipe!!! There was even a band clamp on there, and that was welded to the i-pipe too, WTF! So, I had to cut out the y-pipe and then I could remove the headers. I had already broken two bolts on one header so there was no going back.

The MAC's went in with a fight. The driver side was easy to put in from the bottom. The passenger side was a bitch. I got it on from the top though w/o lifting the motor, took 15 min or so to find the sweet spot where it would slide in with some force. To connect the y-pipe to the i-pipe required an adapter. I covered both sides with copper RTV and used 3" U-bolts to hold the adapter in. Getting the y-pipe in with one person was a bitch. The ORY didnt have a hanger so I'm pretty pissed about that too. Now my exhaust tips are smashed against my bumper

After starting it up and waiting for the smoke to stop billowing out of the engine bay, I looked for leaks. I only found one on the passenger side AIR connection, bad gasket is my guess. I'm suprised my pos adapter thing wasnt leaking. It probably will over time. The test drive went well, I'm not too happy with the rasp and the fact I have bullet mufflers. Definitly an increase in power, but it's running VERY rich. It smells like a lawnmower thats running rich, and I can smell the gas in my clothes right now.

Tomarrow is a trip to the exhuast shop to have a hanger made and to fix the exhaust tip problem. And then on saturday hopefully im getting a dyno tune done.

[Edit]: I havent had an SES light go off yet, even with the two rear O2 sensors removed, NO O2 simms, and running pig rich.

 

My MAC ORY came with a hanger welded in the stock location. Did you buy them new or used? Sorry to hear about the PITA install. Mine went fairly painless from the top for both sides. I did remove the coil packs and plugs.

 

I bought it used from Jason, overpriced for its quality if you ask me... I also removed the spark plugs, coil packs, and valve covers.

 

No matter how much you lean it out with tuning, any time you've got an ORY you're gonna get that nasty smell into your clothes, espeically with a cam. I had my setup tuned so lean (at idle) at one point that it would hesitate when you tapped the gas, and even still it stunk like hell.....

I'm surprised that you guys had more luck going from the top. I thought the Macs would be similar to my Bassanis as they are both mids. I took one look from the top and thought, 'hell no, not going in that way'. Went from the bottom on both sides and they popped right in like they were born there....

 

thats funny i popped both mine from the top

 

There was no way in hell my passenger side would go in from the top, even with the valve cover removed. I wound up cutting the block casting (anyone who installed macs from the bottom knows what I mean), and removed the starter, and it went right in from the bottom.

Damn, I need a lift....

Tommy

 

I didnt have to cut my block casting, mine went in from the bottom

 

My MACs dropped in from the top no problem. Had zero leaks and no fitment issues. I would have kept them, but wanted LTs with my H/C package. If I were to buy another LS1 daily driver, I wouldn't hesitate to use MACs...

 

Both mine went in from the top. Took off both valve covers and removed the steering knuckle. I couldn't get mine in from the bottom for the life of me.
Of course, I do not have any EGR or A/C to get in the way.