fst100

iTrader: (4)

could anyone verify and confirm for me if I can use the Fel-pro MLS 1161 L-041 and 1161 R-041 for my ’01 LQ4 with 243/799 heads? I think I can, but currently doubting myself. The LQ4 has a bore size of 4.0007 and the fel-pro has a gasket bore size of 4.100. I wasn’t certain if the gasket bore was too large or not. Also is it a good idea to spray the gaskets with copper spray?

69Camaro427

I know the 4.8/5.3 motors use a ls1 gasket when swapped not sure if factory has a special 4.8/5.3 gasket or if they use the same one for ls1/4.8/5.3 which is 3.900, so a little over the bore is fine.

I wouldn't spray the head gaskets they don't need it being tq 75-80ftlb, Spraying the header gaskets wouldn't be a bad idea, especially if you have a broken bolt

02_Orange_D1SC

iTrader: (30)

you should be fine I'm running LS9 gaskets on my stock 4.0 bore 6.0 with no problems plenty people on here are

fst100

iTrader: (4)

ok, thanks guys :-)

batboy

iTrader: (6)

Personally, I'd get a GM MLS gasket. Don't use copper spray on MLS. While a larger diameter gasket will work, you'll lose a little compression. I'd use gaskets for a LS1.

fst100

iTrader: (4)

i already purchased the fel-pro gasket already
the fel-pro are 0.041" if thats what you mean by losing a bit of the compression? i've calculated that SCR would be around 11.7:1
i read that ppl spray the MLS with copper spray so that's why i threw it out there on recommendations, which from the response is a no

69Camaro427

If your LQ4 has the stock dished pistons...I'm calculating almost 10.5:1 with non milled 243/799 with a 0.041 gasket

If it has flat tops like a LQ9 then you would be around 11.3:1 A thinner gasket will bump compression, he was talking about if the ring on the gasket is larger than the bore you will lose some compression, but not much maybe a .1 at most

fst100

iTrader: (4)

ah ok, thansk for the clarification. im running milled 0.030" on the 243/799 (forgot to mention that lol)