L6 exhaust question(s)

[68 IRON]

I was staring at my 6 intake/ exhaust manifold preparing to seperate the two and I noticed the numbers cast into the side 813. Noticed this because someone else on here showed their manifold and it had a different set of numbers. My set came off of a 67 292 and has a two stud exhaust port...thought that was odd because I've been reading that it should have 3 studs down there. And last but not least, will I have to modify the fuel lines out of the fuel pump when I switch to HEI? They look really close to the stock distributor and the HEI one has a very large head.

[RichardJ]

The larger exhaust outlet with three studs was used on the 292 in medium-duty trucks. 1 1/2 and 2 ton trucks would have it.

[geezer#99]

Your hei should fit. The base shaft is longer. Mine did.

[68 IRON]

Thanks for the answers. Nothing quite like thinkin' you have everthing figured out and you get the...oh by the way you have to do this first when you've already stepped neck deep into something! Does anyone know what those numbers on the aft end of the exhaust manifold mean? Mine says 813 and I've seen some other numbers?

[Wrenchbender Ret]

They changed from the 2 bolt to 3 bolt around the late 60's. Either one will work with the coressponding flange. The 292 was a different part/casting # as it was a little beefier around the area where they hook together. They are interchangable though. The 1 1/2 ton up 292 used a 3 bolt outlet with a larger opening & straight down outlet.

[Shaky]

The 813 is likely some GM production casting number or something. The exhaust manifold off my '67 250 has 813 cast in big numbers on it.

My '67 292 says 813 too, but the cast numbers are a different style.

I dunno...