Vortec intake gaskets

[Texas82GP]

So I have a new small block Chevy crate engine with iron Vortec heads. I have a new Edelbrock Performer Vortec intake for it.

Initially, I went to Napa and bought a pair of intake gaskets for a 98 Chevy truck. They sold me Fel Pro MS901312. Their construction is a plastic frame with an embossed 'rubber' seal.

At some point later on, I read somewhere, I think on the Edlebrock website that the Fel Pro Performance #1255 gasket was recommended. This is a thick 'paper' style gasket.

I also have a set of ARP bolts which are specifically for the Vortec intake.

I did some reading today to determine what I should torque the intake to and found a lot of discussion about intake gaskets leaking. Both sets of gaskets I mention above were spoken ill of. Many were of the opinion that the only gasket to use was the latest version (3rd design, I believe) of the GM gasket, part number
89017465, which is a metal frame coated with 'rubber' with embossed 'seals' around the water passages and intake ports. This part number also includes a set of GM bolts that have a round 'nose' that is said to be designed to bottom out in the blind bolt holes on the cylinder heads to prevent over torquing the gaskets. The gaskets also have some metal 'rings' at each bolt hole which are also supposed to prevent over torquing the gasket. Here is a picture of that style gasket.....

There is a Fel Pro version of the above gasket that is included in part number MS98000T but it is a kit that includes the other gaskets for the production truck upper intake, and does not include the bolts, which it says are recommended.

Now the point....Those of you running an aluminum four-barrel Vortec intake, what gaskets and bolts did you use? What was your experience? Any leaks? What would you use? What torque spec? I'm seeing 11 ft. lbs.

I'm kinda leaning towards using the GM gasket and bolts mentioned above. The bummer is I'm using 12 point ARP bolts everywhere on the engine as a detail so I'm torn on using the GM bolts. In the end though I want to put it together once and forget about it.

 

[pontiacgp]

I used the ones in your top photo (Fel Pro MS901312), they worked good but I changed them to the ones in the second photo (Fel Pro Performance #1255) when I changed the cam, they leaked so I went back to the ones in your top photo. I'll be doing some engine work this winter so I am going to change them to the ones in your 3rd photo (GM part # 89017465),....and I have torqued the bolts to 11 lbs. The 11 lbs is critical with the top set that has the rubber diaphragm. The gasket in your second photo leaked but I was told after the fact the bolts should have been torqued to 30 lbs but I have never found any instructions to substantiate that

 

[Texas82GP]

I used the ones in your top photo (Fel Pro MS901312), they worked good but I changed them to the ones in the second photo (Fel Pro Performance #1255) when I changed the cam, they leaked so I went back to the ones in your top photo. I'll be doing some engine work this winter so I am going to change them to the ones in your 3rd photo (GM part # 89017465),....and I have torqued the bolts to 11 lbs. The 11 lbs is critical with the top set that has the rubber diaphragm. The gasket in your second photo leaked but I was told after the fact the bolts should have been torqued to 30 lbs but I have never found any instructions to substantiate that

Now that you say that I think I remember you posting about torquing the 1255's to 30 ft. lbs.

 

[pontiacgp]

Now that you say that I think I remember you posting about torquing the 1255's to 30 ft. lbs.

I did and I was told that by a reputably shop but I could never find anything online to confirm that. I was also told by another reputable shop that is you torque them to 30 lbs some guys have stripped the threads.....that is why I went back to the ones with the rubber diaphragm but I have heard the new GM ones in your bottom photo are the best

 

[Texas82GP]

I did and I was told that by a reputably shop but I could never find anything online to confirm that. I was also told by another reputable shop that is you torque them to 30 lbs some guys have stripped the threads.....that is why I went back to the ones with the rubber diaphragm but I have heard the new GM ones in your bottom photo are the best

Steve, thanks for your feedback. A few more questions if you don't mind....

What type of coolant/antifreeze do you run? I saw some discussion online that Dexcool can become acidic over time and attacks the seals on the type of gasket at the top of my post (MS901312).

When you put on the 1255's and they leaked, what leaked (water, vacuum, oil into intake ports) and did you install them dry or did you put something on them (sealant)?

 

[Bar50]

I have the #1255 intake gaskets on the 383 in my Aero Coupe. Dart Iron Eagle Vortec heads and a Performer intake (to clear the flat hood). Have them on the Vortec 350 in my Hell Camino with a Volvo Penta intake. Also have a set in service on a 400 SBC with an imported air gap in a K5 Blazer.

I think the over torque issues my be with plastic intakes and gaskets like OEM for a Vortec truck engine. My Edelbrock intake and my imported intake both had instructions that called for the #1255 gaskets, no leaks on mine so far. I used Gasgacinch and a dab of RTV around the water jackets with the bead across the front and back of the lifter galley.

Mine has old school green antifreeze.

The can be an issue from electrolysis from water flowing over/thru dissimilar metals like iron block & heads and an aluminum radiator & intake.

 

[pontiacgp]

Steve, thanks for your feedback. A few more questions if you don't mind....

What type of coolant/antifreeze do you run? I saw some discussion online that Dexcool can become acidic over time and attacks the seals on the type of gasket at the top of my post (MS901312).

When you put on the 1255's and they leaked, what leaked (water, vacuum, oil into intake ports) and did you install them dry or did you put something on them (sealant)?

I use the green stuff for coolant and the gaskets leaked oil from the valley into the heads, fouled a few plugs and the gasket was wet with oil where it leaked. I installed them dry with dab of sealant at the corner along with the sealant on the valley ends

 

[Texas82GP]

I have the #1255 intake gaskets on the 383 in my Aero Coupe. Dart Iron Eagle Vortec heads and a Performer intake (to clear the flat hood). Have them on the Vortec 350 in my Hell Camino with a Volvo Penta intake. Also have a set in service on a 400 SBC with an imported air gap in a K5 Blazer.

I think the over torque issues my be with plastic intakes and gaskets like OEM for a Vortec truck engine. My Edelbrock intake and my imported intake both had instructions that called for the #1255 gaskets, no leaks on mine so far. I used Gasgacinch and a dab of RTV around the water jackets with the bead across the front and back of the lifter galley.

Mine has old school green antifreeze.

The can be an issue from electrolysis from water flowing over/thru dissimilar metals like iron block & heads and an aluminum radiator & intake.

Thanks for your reply. What are you torquing the bolts to with those 1255's?

 

[Speedy94c]

I have used the 1255 Fel Pros on all of our race engines for close to 10 years now. I have never had a leak of any sort. I have used them on steel intakes and aluminum intakes as well. I use the stock vortec intake bolts and torque to 30 lbs. I have on several occasions even re-used them when I have had to pull the intake or heads off and not had a problem. I always use silicone to seal the front and rear of the intake and I use a small bead of silicone around the water ports on the heads and put the gaskets on it to help hold and seal the water passesges.
I have had problems with the MS901312 gaskets with leaks when I 1st started using the vortec heads.
I put 1255s on my Monte Carlo SS on my small block 400 and no problems.
Hope this helps.

 

[Texas82GP]

Thanks for the replies guys. I went ahead and ordered a set of the latest design GM gaskets/bolts and will inspect them and make a decision.