I have the intake off the car. I am going to take the intake, runners and plenum to work today and hit them with a weak sand blast. Hopefuly trying to brighten them up. Any tips fo re assembly? I am going to use the Fel Pro gasket kit.

 

I had mine done last year use a good silicone prone to leak in back near firewall.Let it sit overnite to allow silicone to set up according to a mechanic buddy of mine this is the only way to do it, to insure no leaks. Good Luck. Jim

 

there was also a good tip in the forum about dimpling the gasket surfaces with a punch. I did this, applied the RTV, then found that I needed to remove it.... It was a royal pain to get off, which is a good thing when everything finally got bolted down.

 

one very important thing to do when you put it back on.. make sure when you set the intake down, it goes down straight and you do not shift it around to get bolt holes to line up.. if it doesn't set down perfectly straight without any shifting, you might as well pull it up, wipe off the rtv and try again.. fresh rtv wipes off real easy so it's no big deal.. you're liable to get a leak if you shift it at all..

-mikey *4 times a charm when i did mine - lol*

 

Mikey

An easy way around the shifting of the intake is to have someone else line up the bolts holes as you hold the intake and lower it. Let the other person actually install 1 bolt in one of the corner holes, this will give you a better postion to lower the intake.

Vic

 

I found that you need to set close and shift due to clearance with the rear oil sensor pipe. Not a lot though. The dimpling idea comes from JAKE. I used "Right Stuff" on the front and back seals. It is an elastomer that sets fast and is very very tough. Per the recommendations of Permatex, I also used their Hylomar product on the gasket faces around the intake ports and the coolant passages.

 

Use Felpro with the rubber end pieces, not cork... Light film of RTV on the heads and in particular around the water jacket ports... Make sure it is all even and set in the gaskets... Dab the 4 corners with RTV then set the intake in place as you were told in the other messages... Let it sit and cure up then torque it down as per the manual... Simple, did one Sunday...

 

The Fel Pro set came with a tube of silicone. No rubber gasket pieces in the box. Is that silicone good enough to make a good seal? Should I get a different brand of silicone? There was no injector O-rings in the box either??? :(

 

I will say this... Many will say they only use silicone and other will say they only use the gasket set... I am not sure who should win in the end but I trust the good engineers at GM and figure they spent quite a bit of money and time figuring out what was best for the engines so who am I to fly in the face of that?? I have done these many many times and while it seems easy enough, it can really be a bitch in that if you leave even pinholes you will have vacuum leaks and the smaller they are the harder they are to find... They will effect your idle and they will haunt you until you do it right... With that said, it seems evident it is best to do it right the first time and while it seems to be a bit of a pain, it is far less trouble than the alternative... To me this means:

a) Clean all parts including bolt as they come off...
b) Clean all gasket surfaces and I mean clean!! These should be felt as well as looked at... Run your fingers around every surface used by gaskets...
c) Place gaskets in place and use a thin magic marker to mark the outline... If you don't the thin layer of RTV you will use will be all over the place on the heads and will not be covered by the gasket or intake...
d) Make sure all gaskets fit where they are supposed to (hole line up perfect and no less) If not, check where you are placing them to make sure you are not too far up or down the head...
e) Once all is perfect and you have the visual picture of how they will be placed, remove them and spread a thin layer of RTV on the heads in the marked areas... Thin means thin but the most important part is that it is all even... No thick and thin patches... This will not be needed under the rubber end pieces if you use them... If you don't the ends will need to be thicker than the head areas by a long shot... 5/16 to 3/8 thick ...
f) If you do use the end pieces, squeeze some RTV onto all 4 corners where the 4 gaskets meet and again leave it a bit deeper than the gaskets themselves...
g) Look it all over and make sure it is perfect then you and a friend, opposite sides of the car, lower it to 1/4 inch off the deck... Look it over again and place it...
h) Now grab where the carb mounts (or wherever you can hold it centrally) and give it a SMALL shake... If it drops into place you blew it... Start over at b) and try it again... This placement is far too important to just get close to right... It must be right and nothing less...
i) From here there are 2 opinions... Some torque it down now and some let it sit and dry before doing so... I usually torque it now but that is because I use the gaskets and not just RTV... If you do go RTV, I would wait to torque it... I would also not start it until dry with just RTV because there is simply nothing to keep it from being drawn in by vacuum... Either way, I would not consider any real RPMs for 24 hours... Using the gaskets, I start it and let it idle for a few... This brings the heat up and aids in the curing... Then I stop it and leave it over night... Others might say they drive it and they probably do... I have redone to many to be in any hurry...


2 More important points is that as soon as you remove the old intake, cover the entire valley with a large towel... Tuck it up into the inside of the top of each head so no junk falls into your block... Tuck paper towels softly into the intake and coolant ports but do not jam them in... The do not have to meet the surface of the head face they can be deeper because they will drag out the junk when yanked out... After all cleaning you will yank each one and drop them all onto the towel... Then the towel should be lifted in 1 action to ensure nothing gets by it... Blow any of this and you have a serious problem...

The biggest pain of this job it the HEI... When you remove the cap, mark a single mark dead ahead on the distributor itself and 2 marks showing the position of the rotor... The rotor is 1/2 in wide and these marks will be made on both the right and left side of the rotor contact... Look strait down over it to make these marks and they will be accurate... When it is time to reinstall, line it all back up the way it is to go back in and then check the cross bar at the bottom of the distributor (oil pump shaft drive cross bar)... If it is lined up across the car line the oil pump shaft up in line with the car from front to back... It looks opposite but this unit turn as lowered into place and will not be the same by the time it hits the oil pump drive shaft... It will take a few tries and as you go you will see that you will have to position the rotor a quarter turn or so ahead of where it is to end up to compensate for the pre rotation as it is lowered... After a few tries you will begin to see how this works... On rotating the oil pump drive shaft, it will turn so easy there will be no resistance to feel but make sure you use a large screwdriver to do it... Nothing small enough to fall into the hole and get lost if it slips...


Well that is about all I can tell you... It sounds complicated but after 1 or 2 you will see it is fairly simple... Patience and cleanliness are the 2 tools you must have (other than the 9/16 sockets and what not)... Do it right the first time and you will never have to know what a true pain these things can be... I actually did one Sunday and as I was working, a friend of the car owner stopped by and mentioned that he hoped I could get the HEI back in right because on his car, it would not go back in right... Rest assure, he is so very wrong... If you hit a snag, never waste your time thinking it can not be done... It can be all you have to do is not consider that it can't and it time you will see what you are doing wrong... He was a fool and did not understand that if it came off, it will and can go back on... Good luck!!

 

just my .02 but since you're going to have everything apart it would be a good opportunity to put an aftermarket base & runners on and do some porting on the plenum.