hi guys. ok, i have my gaskets now and i'm in the process of putting the 340 4bbl intake manifold onto my 318 and need to know the correct procedure for installing the gaskets and sealer. please keep in mind this is the first time i've ever had to install an intake manifold.

do i use the front and back gaskets or do i just use a high temp sealer? i've hear of people using these rubber gaskets and they end up popping out when torquing the bolts down. do i use sealant on both sides of the gaskets? is it easier to put the gaskets down on the heads, then lay the manifold down?

this engine noob needs to know the correct steps and tricks (if any) and i'm sure i'm making this out to be more complicated than it really is!

thanks for any tips and info!

Put some clean paper towels or similar in the ports to keep debris out of them and a clean shop towel large enough to cover the flat valley also to keep debris out. I use gasket sealer (not RTV) on both sides of each of the 8 intake port cutouts on the 2 side intake gaskets and I use a dab of super glue at 3 or 4 places adjacent to the port clusters to hold the gaskets in place on the head intake faces. I do not use the supplied front and rear gaskets but clean the front/rear rails and the matching intake front/rear surfaces and use a wide carefully placed swath of clear RTV instead. Do let it set up overnight. alot of the (supplied) front/rear gaskets in the gasket kits (esp the cork ones) are too thick & can hold the intake up just a hair to where one of the front water ports will begin to seep after a period of time. #1 Clean the surfaces/keep gaskets aligned/no debris on the gaskets/surfaces & I'm a firm believer in using (the appropriate) gasket cement on any gasket whether steel shim (esp needed) or composition. Clean the bolt threads & I dip them in 30 wt oil then blow em off w shop air or even a quick shot of WD40 & go thru the bolt pattern at least 3 or 4 times to 35 lbs (kind of anal but I'm like that) & if the carb is off keep it off until you torque the intake (easier to access all the bolts in a straight line from your torque wrench). EDIT dont forget to drain a gallon or so of coolant out 1st & blow off the top of the eng also to keep loose debris out of the valley area & pull/toss any dowel pins

On my SB with an Air Gap intake, I use Permatex Ultra Copper with the gaskets and lay it around the head ports and across the front and back straps and let it set up for a few minutes. Then I just place the intake on, straight down, and install the bolts. Once they are all snug, I just criss cross them from the inside out. Then warm the engine up, turn it off, and re-tighten the bolts in the same pattern. I've done this several times and never had any leaks or any other problems.

thank you very much guys! that really helps!

Another thing you might want to do while you're at it is use some thread sealer on the intake bolts to keep oil from seeping up through them.

<<<remove any dowels in the end rails first>>>>>>>>>>ask me why ;-(

Heard that the Common blue Felpro intake gaskets are not the best for aluminum/iron combos. I believe they recommend the print-o-seal style, print toward the intake... but back to the question. I too have had little luck with the cork or rubber end pieces as they usually squeeze out or hold the intake higher than the bolt hole alignment allows. I make sure the gaskets are stored flat . circle the water ports with RTV. I also use gask-a-cinch (?) to hold the gasket in place on the head. The gasket usually sits correctly but a few bolts hold it while the gask-a-cinch sets up. Ends are a bead of RTV, allowed to skin about 15 minutes. Set the intake straight down and run the bolts in finger tight. Let set overnight and then torque them down. Generally center on out criss cross, but I have seen almost an outward spiral pattern too on other makes. You can use a 9/16 U-joint socket on the center bolts as the angle sometimes is not straight enough for the torque wrench extension.

On a smallblock, which ports are water ports?

roe

Place the intake on the motor first. Check the alignment if the bolt holes with the intake. The should be slightly lower than the bolt holes in the intake. If the fit is off very much, it will leak water into the engine. I had big problems before I corrected it by having the intake milled on both port sides. If the intake holes in the manifold are low then the gasket and sealer will fix it. If it is high, then you will need to have the manifold milled. Use RTV on the ends and let it set up for 10-15 minutes before installing the manifold. I've tried it without letting it sit and sealing was hit and miss.