C.J.

Ok, I did a search but didn't find what I was looking for. I have a few questions about them, I own a 2000 SS and most websites say that the 2000 model year requires certain extra's for a smooth install. Curious to know what these extras are. Also just kind of looking for an opinion on what ya'll think of them with the offroad y-pipe. I've heard them on a buddies car and it sounded sweet. But I dont see alot of guys on this site that have them listed in their sigs, is there a reason why people opt against the Mac headers. For those who have them what was the install like. Thanks.

Tiger2o69

iTrader: (16)

Most people say they will not give you a substaintal gain. I myself am one of them. GO LT's if possible. You will probably change your mind later on if you do go with them. However there are some guys on here who love them.
If you go w/o cats then you will not need the egr and air type headers. I would leave them off anyway and get get race style headers. The only thing I can think of you might want extra is a block off kit for the egr which can be made yourself.

Refer to jrp's exhaust guid.

Ferocity02

iTrader: (60)

MAC's are great headers!!! The dyno numbers show that the performance gain is nearly identical to long tubes. They make about the same in the top end, but LT's have a little more in the bottom end.

You don't need any extras for the install. You need to get the year 2000 headers, the others wont fit quite as well. The EGR tube I think is different.

Tiger2o69

iTrader: (16)

They make about the same in the top end, but LT's have a little more in the bottom end.

That sounds kinda backwards???

C.J.

There really is no 2000 model year Mac Headers. There is only 98-99 and 01-02 thats why I was asking about the extra parts needed since on a website such as ls1speed they say 2000 model years require certain modifications/extras.

BlueSix

If you are going to do headers, do it right and get long tubes. They are, in every way, more better.

FRCBobby

iTrader: (27)

I have searched and wondered what kind of hp difference there would be between these and LT's. What kind of difference do you guys think there would be 1/4 mile wise?

I had LT's on my LT1 car and the ground clearance wasn't the best in the world, but of course it was lowered, but does the 1.25 that the Hotchkis springs lowered the car make that much difference?

Tiger2o69

iTrader: (16)

My car isnt lowered but the headers are not the lowest part of the car.

Extra parts would be the block offs for the egr and air. Make them youself or buy them for like $20.

Usefull info.... I would buy copper gaskets and puts some ngk tr 55 plugs while your at it

Ferocity02

iTrader: (60)

I thought MAC did have 00 headers... since they don't, you will need to buy an EGR tube from a different year, or just remove the EGR all together...

JEB99TA

iTrader: (32)

Looking at many signatures here, with similarly modded F-Body's, the dyno numbers seem to be about the same (LT's vs MAC's w/ORY). The track times don't look much different, either. The MAC mid-length guys seem to actually see 1-2 tenths better 1/4 mile times. Maybe it's only because they have a little more torque down low and cut better 60' times ... on DR's. Dyno's seem to support similar numbers between the two exhausts, as well.

JEB99TA

iTrader: (32)

To further clarify the point I was making above: It should be a matter of personal choice to what fits your goals, because, there can be so many variables between two differently 'similarly modded' cars. I was indicating that I was seeing a pattern begin to develop. You'd probably see a different pattern in the other direction with 20 DIFFERENT similarly modded cars.

Keep in mind, though, the cars I looked at were all with common mods, and were all in the 12 -13 second 1/4 times range. I think the H/C cars would see better times with LT's ... (IMHO) based on what I've seen here in other posts.

evil02z

I've had MAC's with ORY and I now have Hooker LT's with ORY. The MAC's have better ground clearance and the ball type seal they use doesn't require flange gaskets. The LT's will give you more top end power because of the design. The MAC header doesn't have as good a build quality as most LT's. THe MAC's wil give better bottom end because of the smaller primary tubes. With a H/C package you will probably lose 10-15 HP With a basically stock engine you will probably lose 3-5 HP. Wiegh the difference cost, fit, power gain, and future mods.

JEB99TA

iTrader: (32)

... sounds about right. The primaries are 1 3/4" for the MACS I ordered, but, are welded on the inside/end of the pipe, where they bolt up to the heads. Mine are re-welded on the outside and then ported inside to open up the primary to it's max possible size. I did the MAC's to save money ... free shipping, no tax, and the total was $509.00 flat, including the ORY. Ease of installation and placement of EGR/AIR fittings helped me to decide, as well. Also, placement of the front O2 sensor bungs.

It all depends on your budget and what your goal for your particular application is. Good luck in making your decision.

Dip Stick

iTrader: (1)

I have the macs and the catted y-pipe. After a good tuning when I got them installed I am at 340hp and 249.5tq. Which is similar to the dyno'd numbers of many other guys here with similar mods.

The rest is in my sig. Have yet to go to the track. As for fit n rattles n such. Same as any other I would imagine. Avoid potholes and speed bumps

8banger

iTrader: (16)

It may not mean much, but I love my MAC's. Originally bought them so I wouldn't lose ground clearance and I cannot complain about the power they make and the way they feel down low.

C.J.

Thanks guys for the input