dereknkathy

The rockers will work on the head they left chebby with. Do the paint thing anyway. That shows how much metal you have on other side of the gasket. A few gen 5's had very little metal backing up the gasket where the MK 4 cooling hole is. Your old head has no rocker studs. Just a big 3/8th bolt with shoulder on it. Look at new heads. Studs with jam nuts above the rockers. 7/16th thread. Not interchangable. I assume new heads came with rockers? Pushrods. There is a slot in the guide plates for the pushrods. 5/16 or 3/8 the 2 sizes. See if your pushrods fit the new guideplates. If they are loose, try an intake manifold bolt in the guideplate.

dereknkathy

The spot where gasket blew. Drop a large flat file on head deck and see if all the black stuff comes off. That way you can't concentrate on the bad spot till you turn it into a low spot.

dna

Sorry, but not sure what this means. Do I use my original rockers and arms or the ones that came with the newer heads?

Thanks

dereknkathy

You can not use the gen 5 rocker on the MK4 head. The older head has a 7/16th threaded stud. The newer head (your old one) has a 3/8th bolt.

dna

Thanks for the all the info and support. I took a good look at the original head and the new ones, and the original gasket and the one I bought. I'm good to go. Changed my mind - gonna do both head replacement tomorrow. Likely won't get it all done, but hoping to at least get one side fully done and the other head off.

Gotta also get my flat black spray can out - gonna repaint the new heads as they are orange, and then spray the exhaust and riser manifolds.

I'll keep you posted.

dna

Just spent the last 2-3 hr cleaning off the faces of the block, both heads, exhaust manifold, risers, and intake. They are cleaned, acetoned, true - ready to go.

During cleaning the intake, the little arm/bracket that attaches to the carb feel out of the housing thing. It has a spring inside - I think this rod returns the carb throttle to idle positition. What is the trick to get the rod back in, or do I need a new spring housing?

Thhanks

dereknkathy

It is a heat spring for the choke. Without it, the boat will be very difficult to start, when your kid's are ice skating on the lake. If you don't get it reconnected, it won't have that much effect. Many boats have the whole choke flapper and surrounding air box removed. Look at a dominator or quick fuel. No choke whatsoever. I still want pics of cleaned up block deck. Glad to hear you aren't trying to finish in time to go out today. So. Get heads on, get valves adjusted, and let's see what compression test says...

dereknkathy

I also want a flash pic of inside exhaust manifolds. What head gaskets you running?

dna

Here are a bunch of pics. I'm using the felpro 8523pt1 head gaskets - just came back from the parts store and found these are the basic - they have heavy duty which I think are 805. Problem is they need to order them which will take a few days. I'm thinking I will put on the one side today with the 8523 gasket and then maybe use the more heavy duty for the other side - would that be an issue or should I just wait the 2 days until I put the head back on?

Did .003 feeler gauge on both heads and the block - doesn't go under anywhere

dereknkathy

All the pimply, golf ball looking pattern on the block deck is head gasket residue. Try to get that cleaner. Single edge razor blades and 180 sandpaper folded around flat piece of wood. The exhaust manifold. You see the corrosion-pitting just below the riser gasket flange? These manifolds are not long for this world. Dont do any sanding, wire brush, etc in there. It will just speed up their demise. Do not replace the risers. The are stainless and no longer available. New ones would be standard iron.