I'm a newbie to this forum--but I've been periodically building engines since I got my brand new Snapon Torque Wrench in . . .1971. Not exactly a newbie to turning wrenches.

So I went ahead and replaced the valley pan on my 5.2 (96.) I did not use gasket goop on the water jacket seals, just at the corners like the instructions (and good practice) say to do. Then I start to do the torquing down of the PLENUM, holy crap! It took me 10 cycles to get the torques up to the 12 ft lb spec. What's with the low torque values? Common sense & past experience would suggest torquing the plenum to around 27 ft. lb.

I've read that the we replace the plenum bolts because they're torque to yield. Which may be why I had a hard time getting the torque values to hold at 12 ft. lb. They do seem to be holding at the higher value tho. My inclination, if the issue ever comes up again is to source some non TTY fasteners & not worry about it.

Well, I've been dealing with coolant leaks at both the front & back of the engine. A lot of coolant loss, so today, I retorqued the plenum to what I think is a more reasonable value (which coincidentally is about 27 ft. lb.)

And I reinstalled the bolts for the water pump--used permatex copper rtv on the heads and threads. & torqued it on at about 35 ft. lb.

I've had it to full op. temp. and the leaks so far haven't come back. I share my space with a dog & leaking toxics onto the carport floor is not an option. Seems to run okay, too.

 

i hope you got the billet pan from hughes so you dont have the problem again, othersie your gonna be changing that gasket again in about 80k miles

 

Actually, I bought a chunk of 1/4 inch aluminum plate and made my own. That Hughes kit is very nice, but kinda out of my price range. And we have an excellent source (Tucson has a brand new Industrial Metal Supply store!) for small quantities of plate--and it only costs a buck & a half a pound!

Took some grinding (router bit chucked into a drill press) to get the shape right. I used the new valley pan gasket as a template. It seems to fit fine and works okay. Cost me less than $10 plus the gasket set from Rock Auto.

 

For your sake I hope I'm wrong but I fear the next problem you're going to have is leaking head gaskets. The intake manifold is shaped like a wedge and by over torquing the bolts your applying more than twice the pressure on the heads as should be not to mention even more pressure as the engine heats up and everything expands. Hope I'm wrong and good luck.