I just swapped out a 350 for a 396 bored to a 408 in a 1970 chevelle. Can anyone tell me if there is a problem with the valves staying oiled on a big block running tall valve covers as compared to short? It is possible for me to run short covers, but I had a new set of tall covers that I would rather use. I also have a/c and was wondering how to mount the compressor on the driver's side and what brackets to use. I have the old brackets from when I had a small block but I doubt they will fit. There is also the passenger side cover barely clearing the a/c box(about an 1/8") on the passenger side, I am not sure if that will hurt the a/c box or valve cover when the engine rocks. I have put in new polyurethane motor mounts to stiffen up the motor.

No oiling problems on my 468 BBC. Might run into some clearence problems with the booster (if applicable), but that depends on the covers themselves.

Chris

I have the same set up, you will need new brackets for the a/c and will not be able to run the tall covers because there is a bracket that goes from the a/c compressor to the intake manifold that holds the whole thing in place and with my low valve covers there is only a little space between tha a/c bracket and the valve cover.

I figured that the tall would not work...just thought I would take a shot that someone would know of a way to make it work. I will have to got to the short ones then. Can you tell me where you got those a/c brackets and how much did you pay?

I dont remember where I got mine it was a few years ago, Try Ground up I think they have them. http://www.ss396.com

Would it hurt anything to massage a dent into the a/c box where it is tight against the tall valve cover? How much should this engine move with polyurethane motor mounts? Would it hurt anything if the valve cover bumped the a/c box? By the way...just got her fired up! Sounds great.

The_Wheel1,

Most of the a/c evap boxes I've seen are fiberglass, so you can't dent it, only break it.

I think 1/8"is getting pretty closebest to checkhow much clearance when you get into it while driving. Revving the engine in the driveway probably won't show the true amount of engine movement, but if you have someone handy it will give you an idea. The other thing is to stick some putty onto the a/c box, drive carefully, then check, work yur way up to full throttle checking each time to see how much clearance you really have.

If you don't have much clearance and the engine torques over and hits the box, you run the risk of fracturing it.

As far as the a/c brackets are concerned, you'll be way better off getting the proper BBC a/c brackets. The top bracket that bolts to the compressor and the intake will need spacers or an adapter bracket to make it work, but make sure whatever set up you use doesn't interfere with the carb linkage.

John

Thanks for the tips. We just did a check on the clearance and it seems to be OK. I will try the putty just to make sure though. As far as the a/c bracket goes we are going to fabricate a bracket similar to the original. If it doesn't work then I will change the valve covers back to the short ones.