Ive got the copper gaskets that are coming with my MAC's and am wondering if I should use RTV on them, or ditch them and go with Felpro's and using RTV on them.

 

I dont think you should use any RTV on either of those gaskets. Deffinatly not with the fel pros. Coppers you may need some sealer but i doubt RTV is what you would use.

 

Don't know about the RTV, but I'd go with the fel pro "D" port gaskets. Also, do yourself a solid by making certain that your flanges are all nice and level so that you don't blow a gasket simply because of a bad fitment. And before you nail'em down make sure you have the best fasteners that will allow the best access for installation and tightening if necessary.

And...make sure you have all wires, hoses, boxes, etc. sufficiently away from the headers so they won;t get burned. JMHO

 

I put it on my felpro D port (1074s I think). No problems after more than a year of driving. I have no idea about the copper ones though.

 

Nope, 1074 is the Fel-Pro LT1 head gasket.

 

1406 I think.

 

Yep 1406 is the number.

 

Well help me out cause on the Advance Auto site these are the only Felpro's listed, so is that the 1406?: http://www.partsamerica.com/ProductD...ype=96&ptset=A

 

are they the 1470's?

 

Just get'em though Summit. I went to your site and couldn't even get to the gaskets. Wierd.

 

Well it looks like Fel-Pro has change their numbers:
From the
http://www.federalmogul.com/cda/chan...2_7106,00.html
"Vehicle Application Catalog"
Exhaust Manifold Set
P ENG CODE
USE w/INST AID RED3, BLU4, YEL5 MS95585 93-97

Looks like MS95585 is the new number.

 

Both Jegs and Summit show the Fel-Pro part number to be 1470. I think the number you are looking at is just a stock replacement part. The 1470 is a Fel-Pro High Performance gasket.

 

If you use the copper ones just make sure you have a good set of header bolts that you can torque down good. I would not use a gasket sealer on these.
If u decide to go with the felpro's get the 1406's they are "D" port and are a little bigger than 1074's. also on the package of the 1406's they say they are for a small block chevy from 1955-1985 thats probally why they dont come up as a LT1 gasket.

 

The 1406s are designed to fit the Brodex Track l heads and are a bit larger than the 1470s.

1406: port ht. 1.530 cost: $15.88
port wth. 1.630

1470 port ht. 1.390 cost: $32.69
port wth. 1.410

I don't have a clue as to the difference in price since they are both steel core laminates. Only that they are both "D" ports.

The 1470s do state the style as LT1/Lt4s where the 1470s just say "D" port and add that they are designed for the Brodex heads.

I have the 1406s on my SLP dual-cat shorties (97SS).
I guess you'd have to know the actual size of your exhaust ports to determine whether the larger 1406s would be more appropriate.

However, if the 1406s are larger than necessary, I don't see what the problem would be anyway, since the job is to seal the headers to the heads and would not affect the flow. Now if the 1470s were smaller than than the exhaust ports or the header ports there could be some restriction.

My advice would to go with the larger 1406s ...and they cost half as much as the 1470s. Your call.

 

*WARNING* FELPRO 1406 WILL NOT work with your mac headers....

Mac uses the outside bolts on the heads...unlike any other aftermarket header i know of, I originally bought the 1406 and it will not work..

You'll have to use some sort of stock replacement type, I got Mr. Gasket header gaskets (from Autozone) they seem to work GREAT!

I don't know if it was a coinsidence or not, but i used a LT1 copper gasket originally and i LEAKED from EVERY port.... IF you do use the copper gasket that came with the kit USE Copper RTV or you will leak....torque them down TIGHT too.

I just know from experiance.

Good Luck.