Sealing intake manifold?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

ChuckN

Full Access Member
Joined
Nov 8, 2022
Posts
2,152
Reaction score
7,909
Location
Bellinham, WA
First Name
Chad
Truck Year
1981
Truck Model
C10
Engine Size
350
@Ricko1966 I at least know this- the 1206 gasket that Brodix recommends was a no go. The manifold sat so low that it would barely seal at all. I did not even try with them.
You must be registered for see images attach

I found out about that FelPro makes a thicker version of the same gasket, the 1266 that effectively raises up the manifold. So I did a test fit with them and this is what it looked like and was much more centered, to the extent that the bead of RTV to close the china wall gap had to be rather thick, but was still doable. However- even though the height is centered now, that would not tell me if I have a gap on top or at the bottom sealing surface if the angle is off. And yes, this is the gasket that had issues sealing with the corner bolts bottoming out.
You must be registered for see images attach

I have read about people cutting a hole in a gasket surface top and bottom, putting lead shot in the hole and clamping it down to see if there is a difference in tolerance between the two. But it’s an old technique and I hear lead shot is just about impossible to find. Play dough may be the answer for a makeshift plastigauge.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
10,124
Reaction score
19,531
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
@Ricko1966 I at least know this- the 1206 gasket that Brodix recommends was a no go. The manifold sat so low that it would barely seal at all. I did not even try with them.
You must be registered for see images attach

I found out about that FelPro makes a thicker version of the same gasket, the 1266 that effectively raises up the manifold. So I did a test fit with them and this is what it looked like and was much more centered, to the extent that the bead of RTV to close the china wall gap had to be rather thick, but was still doable. However- even though the height is centered now, that would not tell me if I have a gap on top or at the bottom sealing surface if the angle is off. And yes, this is the gasket that had issues sealing with the corner bolts bottoming out.
You must be registered for see images attach

I have read about people cutting a hole in a gasket surface top and bottom, putting lead shot in the hole and clamping it down to see if there is a difference in tolerance between the two. But it’s an old technique and I hear lead shot is just about impossible to find. Play dough may be the answer for a makeshift plastigauge.
Plumbing solder, been using it to check clearance since mid 80s. If you bolt the manifold to
 

ChuckN

Full Access Member
Joined
Nov 8, 2022
Posts
2,152
Reaction score
7,909
Location
Bellinham, WA
First Name
Chad
Truck Year
1981
Truck Model
C10
Engine Size
350
Plumbing solder, been using it to check clearance since mid 80s. If you bolt the manifold to
So maybe no gasket, hang a couple strands of solder vertically down the surface and clamp it? I like the idea.
 

aasleson

Full Access Member
Joined
Mar 27, 2025
Posts
139
Reaction score
601
Location
Minnesota
First Name
adam
Truck Year
1986
Truck Model
k30
Engine Size
6.2
We use lead balls for figuring out shim packs for final drive preload on john deere tractors. If you have a deere dealer close I could find a part number for you.
 

ChuckN

Full Access Member
Joined
Nov 8, 2022
Posts
2,152
Reaction score
7,909
Location
Bellinham, WA
First Name
Chad
Truck Year
1981
Truck Model
C10
Engine Size
350
We use lead balls for figuring out shim packs for final drive preload on john deere tractors. If you have a deere dealer close I could find a part number for you.
What approximate size would they be? Probably wouldn’t want any bigger than .125. Thanks for that offer!
 

aasleson

Full Access Member
Joined
Mar 27, 2025
Posts
139
Reaction score
601
Location
Minnesota
First Name
adam
Truck Year
1986
Truck Model
k30
Engine Size
6.2
What approximate size would they be? Probably wouldn’t want any bigger than .125. Thanks for that offer!

R72232 is the John Deere part number, shows the balls themselves start off at .32 In. I can't remember off hand what they crush down though.
 

Forum statistics

Threads
48,620
Posts
1,072,758
Members
43,237
Latest member
Sloestang
Top