Macadoo

Hi guys,
This is asking a lot but I was wondering if someone could outline re-gasketing a '71 350. I'm ready to start putting mine back together but am confused by what gets adhesive, what gets rtv, and what gets nothing. And most of my gaskets have no instructions. All gaskets are Felpro.

1. Blue timing cover paper gasket - rtv, adhesive, or nothing?

2. Water pump blue paper gasket - rtv around water holes only?

3. Cork oil pan - rtv, rtv where end seals join gasket only, rtv between cork and block?

4. Oil pan rubber end seals - adhesive only?

5. Intake I think I get - rtv for front and rear seals, overlapping the gasket just a bit, nothing on the sides.

6. Felpro blue head gaskets - instructions say no rtv or adhesive.

7. Thick rubber valve cover gaskets - maybe adhesive on cover side only?

8. Mechanical fuel pump (grey paper) - no idea on this one

9. Thermostat cover gasket - rtv both sides of gasket?

Many thanks!

MDchanic

You may get different opinions on this, but...
RTV all over these, as far as I'm concerned.
And I prefer the rubberized Diesel oil pan gaskets to the cork ones.


FelPro intake should come with instructions and a little tube of black RTV. The RTV goes pretty much everywhere, in a very thin layer.


That all sounds good. RTV all over the fuel pump gasket as well.

Others may say to put RTV on only one side of a lot of these, which is fine, but my priority is keeping it from leaking, not in being able to take it apart.
If it needs to come apart, I'll manage, then clean the surfaces again and replace the gaskets.

Just my own opinion.

- Eric

Macadoo

Thanks Eric. Much appreciated, as usual.
"And I prefer the rubberized Diesel oil pan gaskets to the cork ones."
Same year and displacement? I wasn't too keen on the cork myself. I pulled this motor mainly to stop all the leaks. That's my main objective.

MDchanic

As listed here, it's the FelPro OS30471C.

- Eric

olds 307 and 403

I just did my 350 with the Fel Pro gasket set without head gaskets. The turkey tray, use RTV around both sides of the gaskets where the four water ports at the end of the gaskets. I was going to use the Ultraseal 3 intake gaskets I got from Cutlassefi. My Performer was not flat and it would not bolt up. Plus RTV instead of end rail seals. Cork is fine for short term sealing. I put RTV on all the gaskets, just to be safe. I also used the AMC rear main rubber seal, only thing leaking but very minor at that.

coppercutlass

Just no rtv on the head gaskets.

Macadoo

I used the Ford 292 rear seal. Went in without a hitch so fingers crossed. Olds, your performer wasn't flat? Was it new?
Turkey pan instructions say a thin bead around the intake ports, both sides. An eighth inch bead around water holes both sides. Definitely RTV instead of end rails.
RTV on top and bottom of the front and rear pan seals?

Eric, thanks for the link. I'd seen that at one time but couldn't find it again. But to be honest, I didn't try real hard.

Macadoo

I found the rubber gasket at Advance Auto. It says it's an exact fit for my 71 350 but I had read it needs trimming. Which is true?

MDchanic

I think it doesn't quite mesh exactly with the front half-round rubber seal, but you use RTV at that point anyway.

And I'd use a thin coat of RTV top and bottom on those end seals, as you noted.

- Eric

Macadoo

Thanks Eric

olds 307 and 403

I bought the intake NIB off EBay, supposedly a common problem. My RPM worked fine with thick intake gaskets. I also use Permatex Aviation brush on sealant around the intake ports.

joe_padavano

With specific exceptions (the water ports on the turkey tray intake gasket, front and back intake seals, or the joints between the oil pan side rails and front/rear rubber gaskets, for example), a quality gasket shouldn't require RTV to seal properly if the mating surfaces are flat and the fasteners are torqued correctly. I don't use any sealer except for a little gasket tack to hold the gaskets in place during assembly. I use RTV on the three specific areas I listed above, as well as on the bolts for the t-stat housing, which thread into the coolant crossover.

olds 307 and 403

Problem is finding quality gaskets for our old junk. Cork is old tech, becomes brittle over time. I reused my Permaseal valve cover gaskets, supposedly Fel Pro stopped making them. The only way I could seal my Edelbrock signature series valve covers on 5 bolt 307 heads was straight RTV. I tried the thin rubber and also cork gaskets. Some supposedly have had clearance issues with the diesel oil pan gaskets. I know Milidon and Corteco have fiber pan gaskets, they worked Ok for me. Others didn't like the minor seepage. SCE has rubber pan gaskets but 3 piece, a 1 piece would be nice. I may try the Mr Gasket rubber cork valve cover gaskets when the 350 goes into the 4x4.

Macadoo

Good stuff, guys, thanks.

coppercutlass

I have had good luck with the rubber gaskets for the valve covers with no rtv. My friend worked at a mold shop and he made me studs for the valve covers which anyone can buy but I got free. Having the studs is awesome for gasket alignment. Previous to me puting studs for the valve covers I would occasionally pinch the gasket or it would move etc. Although it would be easy if I used rtv I don't like using rtv on the valve covers. If done right they should not leak.

Macadoo

That's what I have. Thick rubber from Felpro. And I like the studs idea. They would go well with the chrome covers I'm hoping for for Christmas.

coppercutlass

I think arp sells them in nice stainless with chrome nuts to boot or polished.

costpenn

Spoken like someone who had real world machine shop experience. If only all my customers would understand these basic concepts.