Emergency Please Help!

[garybuick]

Im in the process of replacing my 73 2bbl intake with a 70 4bbl intake. Everything looked good, got the right gaskets, went to put it on and there are some holes exposed on the heads that arent being covered by the 4bbl intake!!!

They must be some heat riser holes or something. Im guessing that if I install the manifold basically exhaust will come out of those holes and it will be loud.

My sealer is getting dry, the intake is setting on the engine ready to be torqued down? What can I do? Can those holes be filled with jb weld epoxy or must they be drilled and tapped? and can that be done on the engine? The engine is in the car and I need that car to get to work later this week??

Please help ?

Thanks
Gary

[mltdwn12]

Those are probably the air injection holes used on later motors. I had a set and ran across the same problem. Not sure if it was the best way, (20 years ago!) but I found some bolts that were very snug, put JB Weld on them and tapped them in. Then sawed the head off. Never had a problem. :)

[garybuick]

thanks a lot. Ive got it all back together now. Im going to try JB weld alone and if it doesnt work, ill find some snug bolts like you did. Thanks.

Gary

[Hector]

Gary,Craig is correct,those are for the air injection system.If you can measure the holes you may find an expansion plug that you can drive in there or have some soft plugs,maybe AL,to plug them with.Good luck.

[garybuick]

I havent started the engine yet. Is it possible for me to take the manifold off, put the plugs in, and put the manifold back on the same gasket? or must I get a new gasket. Once again I have not started the engine yet, the gasket is brand new. ?

Thanks

gary

[bobc455]

As far as I know, you need a new gasket. I've never reused an intake gasket.

-Bob C.

[garybuick]

Gary,Craig is correct,those are for the air injection system.If you can measure the holes you may find an expansion plug that you can drive in there or have some soft plugs,maybe AL,to plug them with.Good luck.

I think the holes are 3/8 I dont know didnt measure otherwise i would have noticed them and not put the intake on. So now the intake is on. I started it up and it ran good, made a helluva noise and exhaust. Not good. its not drivable this way even temporarily.


So Auto parts store has 3/8 freeze plugs. I think thats the size can anyone confirm? Will these freeze plugs work to plug these AIR holes in the heads. The manifold covers half the hole. I ordered a new gasket set. 28 dollars.

Please advise. thanks

Gary

[moleary]

It’s been 25 years since I have played with the 350, but, I know 70 is different than 72 as far as water jackets in the heads to the block; not sure about the heads to the intake.

Unless someone can confirm compatibility, before you start this engine up, perhaps you should drain engine oil, fill system with water leaving oil plug out just to be sure.

If no water escapes out the oil pan, you should be ok. Fill up with oil and let er rip.

[garybuick]

man I would have thought this would be a common swap. I had no idea it would be so uncharted territory at this point in 2009. I measured the holes and reamed the carbon out. They appear to be 5/16. A 5/16 drill bit can be forced into it so it may be slightly smaller. Im debating whether to tap threads and use pipe plugs, or get some aluminum round bar 5/16 and cut some plugs and tap them in. What would happen when it all heats up? Would they expand at different rates and then the plugs get loose and fall into the passageway? and end up getting stuck in the exhaust valves?? Ouch!.

[garybuick]

Update,

there are 8 5/16 holes in the head. So went to hardware store and got 3/8" set screws. got my 3/8 tap out and went to work. Did 3 holes perfect, set screws went in perfect. All is well. 4th hole and then ill break for lunch..

broke off the tap. damn! now what? i could file it down and leave it in there but it might leak? I have an easy out bit. never used one before. I could try that. If it came out , all would be well. Plus bits of the tap when flying. I dont know if any got in to the ports on the heads. I had the cam shaft area covered up with shop towels but some may have got by the ends. Just dont know. This is turning into a pain in the ass. I have no car so all runs uptown are on bicycle. Thankfully its warm here in florida.

suggestions.