Help with 1969 Chrysler 70hp

[huskerdaninva]

Hey again y'all. I need to pick someone's brain who is more knowledgeable than me. I have a 1969 Chrysler 70 hp that I brought back to life last fall with much help from you fine folks. I'm currently in the middle of doing pre-season maintenance on the powerhead and lower unit.
Eng. Model # 7071 / Serial # 5145.
I've already ordered a new impellar and have new check valves coming for the fuel pump. My issues start with the thermostat and cylinder head. On my motor one has to remove the cylinder head cover to access the thermostat. There is no separate cover for the thermostat.The bolts that hold the head cover go thru to the block and also secure the cylinder head too. I need new gaskets and I have found that the part number for the head gasket is 18-3855 and is available for about $30.00. Does anyone know a part number for the thermostat and the cylinder head cover gasket. This gasket has portions that extend across the diameter of the circular open area. (Hope this makes sense.) All of the charts that I have found list Chrysler 70 hp only as far back as I believe 1977.
OK, now if I can't find a gasket can I use permatex in lieu thereof? Same question on the gasket that goes under the metal plate under the waterpump impellar? Will permatex or something else hold up or are gaskets the way to go? Oh yeah, is it safe to use teflon tape on the threads of the vent/fill plugs on my lower unit? They seem to be seeping a tad. Is there a part number for the plugs available? Thanks I know I'm being a pain but this board is such a vast wealth of experience and knowledge. Thanks in advance for any help!
Dan

 

[mrwiggles2]

Re: Help with 1969 Chrysler 70hp

Gaskets are a must, I don't think the permatex option is the way to go under the water pump. I had to get a new head on my 70 hp last summer, two stripped plugs. I only replaced the head gasket if I can remember. I took off the head gasket not the cylinder cover as you. The newer head was better than the head from '73 because you can access the water pump without having to take the entire cylinder head off.

I used teflon tape on my vent plugs because they were weeping. But, that was only a quick fix to keep me floating. Once I did the lower unit seal kit, I put new seals on the entire lower unit which made a huge difference. I was pleasantly surprised that I did the LU seal kit replacement and it went well. Nice to have new water pump, seals and oil. Reassuring on the water. May have the motor professionally tuned- especially the carbs.

 

[Frank Acampora]

Re: Help with 1969 Chrysler 70hp

The gasket for the head cover is not a necessity, it was not used on later heads, and indeed it does tend to cause corrosion internally because it traps water against the casting. Take the cover and using a little lapping compound fine sandpaper, or sink cleaner (the gritty kind) smooth and flatten the head and cover mating surfaces against a glass plate. Then use permatex to seal them. Hopefully, they will not leak around the plugs. Be certain to use anti-seize on the three 1/4 inch bolts next to the plug holes. (or two bolts and one overheat switch)

Permatex will not do in lieu of the water pump gasket. If you can't find one, make one from 1/32 inch gasket paper available at the auto stores. It only takes about 10 minutes and you can use a child's punch for the bolt holes. Use an exacto knife for the slots and be accurate with them.

 

[huskerdaninva]

Re: Help with 1969 Chrysler 70hp

Thanks for the info guys. I've got my new thermostat, water pump gasket, (2 ea., in the kit, I assume that one goes under the steel plate, and the other between the steelplate and the impellar housing.), and two new magnetic drain plugs for the lower unit.

Frank, as far as the cylinder head cover gasket, or lack thereof, goes I understand you to be telling me that I can use permatex in lieu of this gasket provided that the mateing surfaces of the head and cover are clean, true, etc. I imagine that I'll have to pay attention to the area surrounding the plugs to ensure a good seal. That sounds like a plan. Out of curiosity, the old cover gasket had the portions across the circular openings, but did not seem to contact anything. What was the purpose of that portion of the gasket?
Thanks again for the help.
Dan

 

[huskerdaninva]

Please disregard this post I made a mistake!

Please disregard this post I made a mistake!

Sorry, I made a mistake.