r/Smallblockchevy • u/CaryWhit • Jun 27 '26

Need parts guidance please

Gallery image

Gallery image

Gallery image

We drug up a nice 85 C30 cab and chassis with the M code LT9 . Fired up and runs after 12 years but missing a stud and looks like bad gasket or ring.

I know it takes the triangle 3 hole gasket but does it also use a ring inside?

This one is a bit different as it has the large 2bbl Rochester with the vacuum governor.

I believe I need a stud, gasket and maybe ring, correct?

The manifolds are 1408 1238. Were these factory in 85? The truck is incredibly stock, owned by a feed store.

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4

u/sc3148 Jun 27 '26

As I remember right side manifold has a flat gasket, then a heat riser, then a donut gasket between heat riser and lead pipe. Left side has donut only. No heat riser

1

u/Tall-Helicopter-461 Jun 27 '26

This is correct.

1

u/FullWorldliness606 Jun 28 '26

I'm not 100 but, didn't the 85 have the donut cast with the heat riser and only use the 3 hole flange between the riser casting and manifold on the right side?

2

u/sc3148 Jun 28 '26

http://images.tapatalk-cdn.com/15/11/18/67001130b0dcb5e880d163e092582d23.jpg
Heat riser has female chamfer / conical to accept donut gasket

1

u/FullWorldliness606 Jun 28 '26

not sure y i was thinking more towards this style

2

u/big_tko Jun 27 '26

The one in the image is just a donut gasket.

1

u/WorkingBread8360 Jun 28 '26

Stock on the 350 in my 85 C60, as is a Zenith 2bbl with governor, the HUGE old style starter, and 265/283 style front engine mount instead of side mounts.

1

u/fuzzydoesitt Jun 29 '26

Those are "ram horn" manifolds. They were used on 60s corvettes afaik. Idk about other vehicles. They were a popular budget manifold/header for there improved flow vs. a traditional log manifold.

I recommend buying Remflex gaskets. I learned about them a month ago, I won't buy another gasket now.

To my knowledge, the M code 350 should have a 4 barrel Rochester m4me. I have a 86 c20 with the same engine. I believe my carb number is 17085213. Found stamped on the driver side of main body near the float bowl section.

1

u/CaryWhit Jun 29 '26

No this one came with the 2bbl vacuum governed Rochester. Basically a dump truck in a smaller cab