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Just put body back on my 76 did a total redo on everything from frame and up Installed 454 bb actually 496 with 5 speed tremec.Dougs side pipe headers and steeroids r/ p. Now the problem.Power brake booster hits valve cover.valve cover on driver's side right up against body were booster attaches.Also noticed driveshaft is not centered in tunnel.
2 things , did you change the motor mount frame stands to big block stands? they are a little lower than small block stands. The other is tall valve covers and power brake boosters don't like each other. There is a stock left side cover for a bb w/ brake booster that is even lower in the rear corner.
I don't have any ideas on the trans not being centered, sorry.
Yes- it is a problem. I have manual brakes and there is barely 1/4 inch clearance between my valve covers and the corner of the brake master cylinder mounting space.
I just used a pair of these covers on my 69 BBC with power brakes. It's close, but they do clear both the master and the T&D shaft rockers. Not from this vendor, but that gives you an idea. http://www.yesterdaysmusclecars.com/product_p/a1208.htm
The driveshaft is NOT centered in the tunnel. The engine is offset to the pass side by 2". Motor mount stands are the same big or small block. Oh the joys of building a custom !
Hi gom,
"did you change the motor mount frame stands to big block stands?"
I really don't think there was ANY difference in the engine mount frame brackets on frame that ended up with bb engine compared to one intended for a sb engine. Just 2 frame part numbers, for either a 4 speed frame or an automatic frame.
The engine mounts were the same part too.
Regards,
Alan
Your valve covers are taller than factory or likely even the others in the posts here. Also there is a tall deck version which, as it sounds raises the deck higher. The motor mounts for my 1970 are the same for big and small block. I think the combination of potential tall deck block and taller valve covers are causing your interference. Do you need valve covers that tall, if not you may be able to get shorter ones to work. i believe the height difference is around 0.10 in height, and while may not be much it all adds up. Just my $0.02.
As stated, you can get the BB covers with an indent that gives clearance for the booster. I wish I could remember the company I got mine from but it's been too many years. I got them for appearance only since the chrome had gone away on my originals. I was afraid the chrome wouldn't hold up on the replacements because they were not expensive but it has actually held up perfectly.
I'm not sure if you're running roller rockers. If you are, you won't have clearance for them if you get covers with drippers. I got my covers without them since rollers don't need the drippers to get oil anyway. FelPro makes a double thick valve cover gasket that will give you the needed clearance to run roller rockers under the indented style covers. I hope that all makes sense.
Do this. Look at how motor is sitting in the compartment and you may notice the tunnel is not the issue at all and the motor sitting on its mounts is allowing it to point towards the tunnel . My 4l80e install did that . So I pushed it off he tunnel wall and set the trans mount , tightnened her up and all was well for clearance. DO NOT expect centered in the tunnel it will favor pass side but if u ended up like me you will end up with about 1/2 clearance
I knew my 72 bb had power brakes and those huge looking MT valve covers that didnt hit the booster,
I asked why are some bb covers dented,
I was told they were for c2s with a larger booster, c3 has smaller booster which clears, so why doesnt yours?
Im again curious...
Last edited by The13Bats; Apr 17, 2017 at 02:53 AM.
BB trouble
