Hello,

I have almost finished my LS1 / 4L60 swap into my 1989 Firebird Formula.
Now I am having custom stainless exhaust made and we hit a snag. The right header is different than the left one, it has different exhaust pipe diameter, one has 57 mm and the other 63 mm. Is it normal or have I bought some freaky engine? The engine comes from `98 Camaro.

Also the passenger side header has to small diameter for the exhaust ports in the head and we need to bore it to make it work properly!

I would be grateful for clear information on factory headers for F-car.

Next year when I have LS6 heads on I will order a custom headers, specifically for these heads, cam etc. because those factory headers make the sparkplug change nigh impossible.

Kind regards
Marcin

 

Wow- that's odd... Do you have any pictures so that we can really see what you have?

 

I`ll take them when I get the car back from the mechanic. They made a sleeve in that 57 mm one in place where headers join with the pipe, the exhaust will be connecting into y pipe behind the transmission, due to SPOHN transmission mount. I will loose some groud clearence but it`s the only way to do it. I will post pictures of my exhaust when it`s done.

Cheers
Marcin