Just bought a 1995 GMC C1500

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.

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,828
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
I was looking at the exhaust manifolds, and I don't see any gaskets at all, on either side. Driver side manifold has a missing or broken bolt. I stuck a screwdriver in there, and I think it broke off in the head. Wtf! If it is, I'm guessing it's gonna be a PITA!!! getting it out.
You must be registered for see images attach


You must be registered for see images attach

Do your self a favor before you pull the manifold get yourself a set of transfer punches from HF. Center punch the broken stud then pull the manifold. Transfer punches are a good investment.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Anybody know what gaskets these manifolds take, round, or square port?

IIRC, square and round only matter on Big Blocks.

Just so you know ahead of time, you're most likely to need a manifold spreader to get those back on. Maybe off too. Cuz of the heat, they close up and it's a real bitch to get the bolt holes to line up. So the spreader will spreads the ends open so the bolt holes line up. One the bolts are snugged, you can take the tool out.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
I was looking at the exhaust manifolds, and I don't see any gaskets at all, on either side. Driver side manifold has a missing or broken bolt. I stuck a screwdriver in there, and I think it broke off in the head. Wtf! If it is, I'm guessing it's gonna be a PITA!!! getting it out.
You must be registered for see images attach


You must be registered for see images attach

That is what it sounded like to me, but I thought that would have been obvious. It sounded like real bad exhaust leaks or maybe even a cracked manifold. Hopefully it just is missing exhaust manifold gaskets.
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,828
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
IIRC, square and round only matter on Big Blocks.

Just so you know ahead of time, you're most likely to need a manifold spreader to get those back on. Maybe off too. Cuz of the heat, they close up and it's a real bitch to get the bolt holes to line up. So the spreader will spreads the ends open so the bolt holes line up. One the bolts are snugged, you can take the tool out.

Put the manifolds in the oven for a little while get some heat in then not a whole lot and also take them off warm.
 

VAL

Full Access Member
Joined
May 29, 2012
Posts
893
Reaction score
57
Location
TUCSON, ARIZONA
First Name
VAL
Truck Year
1986
Truck Model
K10 SILVERADO
Engine Size
5.7
Do they make headers that fit, the existing OEM Y piping?
 

VAL

Full Access Member
Joined
May 29, 2012
Posts
893
Reaction score
57
Location
TUCSON, ARIZONA
First Name
VAL
Truck Year
1986
Truck Model
K10 SILVERADO
Engine Size
5.7
And the plot thickens! Was crawling around under the truck, and found this.
You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach

Rear passenger upper shock mount, broke clean off.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
And you'll probably find some more surprises too. You got a killer deal on the truck so you've got to expect a few things wrong. Nothing that can be fixed though.
 

VAL

Full Access Member
Joined
May 29, 2012
Posts
893
Reaction score
57
Location
TUCSON, ARIZONA
First Name
VAL
Truck Year
1986
Truck Model
K10 SILVERADO
Engine Size
5.7
Today I plan on taking the manifolds off the heads. I'm kinda worried about breaking another or a few more bolts in the process. What's the procedure on preventing that possibility?
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Biggest Tip, TAKE YOUR TIME, TAKE YOUR TIME !!! Warm up the truck so they have a little heat on them. Of course be careful not to touch the manifolds and burn yourself. The biggest hurdle is going to get them to crack loose and not break off. If you can get them loose then you can probably get them all the way out without breaking them off. You can even try to tighten a little more and they might crack that way, then back them off a little bit, like maybe 1/4 to 1/2 turn, then go back to tighten, then back up 1/2 to full turn, if it feels OK, back it off some more. When you start to fee them tighten up again, go forward again like you're tightening them, about a full turn, then go back a few more turns. If you play that back and forth game you'll get them out without breaking them. Just be to sure to at least get them all to crack loose while you have the engine warmed up. Just do one side first. Then warm it up again and do the other side. Just got to work them bolts and make them YOUR BITCH, otherwise, they're going to be your bitch. A real big bitch if you break them off in the head.
 

VAL

Full Access Member
Joined
May 29, 2012
Posts
893
Reaction score
57
Location
TUCSON, ARIZONA
First Name
VAL
Truck Year
1986
Truck Model
K10 SILVERADO
Engine Size
5.7
I found the exhaust leak!
You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
NOT surprised. See I told you the video just sounded rattly to me like maybe a broken exhaust manifold. I guess I did hear it right after all.

Oh and I said you're likely to find some more surprises.
 

foamypirate

Full Access Member
Joined
Jul 30, 2010
Posts
3,302
Reaction score
456
Location
Central TX
First Name
Jake (Mr. Wilson)
Truck Year
1980
Truck Model
El Camino, baby!
Engine Size
5.3L/4L60E
That's exactly how the manifold on my TBI 305 broke. Took me YEARS to track it down. Manifold gaskets, donut gaskets, etc. I tried everything. Finally, one time I took it off, the heat shield had rusted enough, and the whole dang thing fell apart. Turns out the heat shield had been the only thing holding it all together for quite some time!
 

VAL

Full Access Member
Joined
May 29, 2012
Posts
893
Reaction score
57
Location
TUCSON, ARIZONA
First Name
VAL
Truck Year
1986
Truck Model
K10 SILVERADO
Engine Size
5.7
NOT surprised. See I told you the video just sounded rattly to me like maybe a broken exhaust manifold. I guess I did hear it right after all.

Oh and I said you're likely to find some more surprises.

Yup, got to give you props on that! I got the passenger side off without breaking any bolts. I loosened the driver side bolts, but it looks like I'm going to have to remove the ps pump to get the fist two out.
You must be registered for see images attach
 

VAL

Full Access Member
Joined
May 29, 2012
Posts
893
Reaction score
57
Location
TUCSON, ARIZONA
First Name
VAL
Truck Year
1986
Truck Model
K10 SILVERADO
Engine Size
5.7
That's exactly how the manifold on my TBI 305 broke. Took me YEARS to track it down. Manifold gaskets, donut gaskets, etc. I tried everything. Finally, one time I took it off, the heat shield had rusted enough, and the whole dang thing fell apart. Turns out the heat shield had been the only thing holding it all together for quite some time!

Yup, that is some covert **** indeed.
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,128
Reaction score
9,299
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Yup, got to give you props on that! I got the passenger side off without breaking any bolts. I loosened the driver side bolts, but it looks like I'm going to have to remove the ps pump to get the fist two out.
You must be registered for see images attach

Can you not just take the bracket off the back of it or is it all 1 pc?
 

Latest posts

Forum statistics

Threads
44,083
Posts
949,050
Members
36,162
Latest member
jbahena95
Top