# 1966 GTO 389 Repair / Refresh Questions



## peahrens (Jun 7, 2010)

Hello, I'm new here. Will be pulling 389 tri-power (rebuilt in 1992) to repair rear main seal and refresh the engine looks, so have a few important questions. Have a valve noise, so may also have to do cam & lifters. Feel free to suggest topics to concentrate on older threads.
a) which rear main seal to use (e.g., BOP viton or Bestgasket graphite)
b) what gaskets best to use for oil pan, exhaust manifold, valve covers, timing cover, intake
c) what color should the tripower carb sections (base, middle, top) and from whom to get the spray paint
d) how many coats of spray engine paint on refresh (ordered 3 cans from hirsch)
e) what's the quality of the '66 chrome valve covers from Year One? I had the originals rechromed locally last time and they didn't get done well, so I'm thinking a better rechromer or just replace (it they really look the same)
f) what restore suppliers besides Year One do you suggest. I haven't kept up.
g) what's your favorite forum(s) for classic GTO's. 
h) if having to replace the cam, I've got a problem. I put a Crane 283801, no longer available. It's a bit hotter than stock tripower but runs great on current premium gas. Do I just talk to Comp Cams and compare specs to get the combination of street power with reasonable idle and no pinging?
i) I'll rebuild the carbs...do you think new floats are necessary, or do I test them??
Thanks a bunch for any help!


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## 05GTO (Oct 6, 2004)

Hello, I'm new here. Will be pulling 389 tri-power (rebuilt in 1992) to repair rear main seal and refresh the engine looks, so have a few important questions. Have a valve noise, so may also have to do cam & lifters. Feel free to suggest topics to concentrate on older threads.
a) which rear main seal to use (e.g., BOP viton or Bestgasket graphite)
BOP viton is pretty good, never used Bestgasket.
b) what gaskets best to use for oil pan, exhaust manifold, valve covers, timing cover, intake. 
I've used several brands, I believe the last kit I purchased was from fel-pro.
c) what color should the tripower carb sections (base, middle, top) and from whom to get the spray paint
I am running a Carter AFB so someone else will chime in.
d) how many coats of spray engine paint on refresh (ordered 3 cans from hirsch)
2 coats should be ok
e) what's the quality of the '66 chrome valve covers from Year One? I had the originals rechromed locally last time and they didn't get done well, so I'm thinking a better rechromer or just replace (it they really look the same)
Mine are remanufactured and look pretty good.
f) what restore suppliers besides Year One do you suggest. I haven't kept up.
My first pick is The Parts Place out of chicago, 2nd is Ames, Third is is a toss up between Performance Years, Year One and OPGI.
g) what's your favorite forum(s) for classic GTO's. 
I'm kinda partial to *GTOForum*, there are alot of helpful guys here without the attacks you see on some forums.
h) if having to replace the cam, I've got a problem. I put a Crane 283801, no longer available. It's a bit hotter than stock tripower but runs great on current premium gas. Do I just talk to Comp Cams and compare specs to get the combination of street power with reasonable idle and no pinging? 
I recommend changing to or staying with a roller cam to eliminate needing zddp.
i) I'll rebuild the carbs...do you think new floats are necessary, or do I test them??
I would do new floats,

Thanks a bunch for any help!

Post a few pictures when you get a chance,


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## peahrens (Jun 7, 2010)

I'll try to attach a few photos.

Thanks for the info.


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## Koppster (Jul 27, 2008)

Great looking car...what part of Texas?

PS: You might want to search the forums about painting the carbs vs having them "treated"....I'm not an expert but I've read that painting is not the preferred method of restoring the color for carbs.

Rick


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## peahrens (Jun 7, 2010)

We're up the road from you...New Braunfels.


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## Koppster (Jul 27, 2008)

I'll be darned, all of 20 minutes...we'll have to meet up someday! :cheers


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## Rukee (Feb 8, 2007)

Nice lookin GTO!!
I'd also like to know what color the carbs are to be painted. I have my bases painted with a 'cast iron' color paint, but the carb bodies and tops are original.


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## geeteeohguy (Feb 2, 2008)

I agree...the vendors have a goldish-zinc carb paint, but I would just clean them and run them non painted. Mine are like Rukee's, and have been on the car and operational for 45 years. They've earned their patina. The floats, if original, are brass. Don't replace them unless they have a leak. Just immerse in a cup of water and look for bubbles, or see if the float sinks. Brass floats last forever. Rear main: I've installed the BOP Viton seals, and they worked well. I've heard great reviews of the BestGasket square-cross-section rope type rear main seal, though, and I would be inclined to try one. A rope type seal is more tolerant of imperfections in the sealing surface.


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## Rukee (Feb 8, 2007)

*rear main oil leak*

I don't so much look at it as an oil leak as much as I do the GTO is just marking it's territory. Somewhat of a male dominance thing.


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## MaL (Jun 12, 2008)

Sweet! More locals. Give me until next summer ('11) and I'll be ready to roll.

As for carb color- I spoke with a Tri-power rebuilder who says you can get them plated to look like original but they will flake over time. Or you can use an Eastwood color that isn't exactly the same as factory, but close, and it lasts much longer.

Mine are grey...kind of like after all the plating is gone.


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## Koppster (Jul 27, 2008)

Interesting PY thread on the carb paint vs treat dilemma:

tri power carb plating - PY Online Forums

Rick


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## jose67GTO (Feb 24, 2018)

peahrens said:


> I'll try to attach a few photos.
> 
> Thanks for the info.


What color is that, look great.


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