Back In Action - With Questions

[rn2fine]

Greetings Everyone,

I hope all is well. I have not posted in a while. Went overseas last year and have been trying to catch up with life since I got back to the states. I have pretty much finished up my 72 Burb (pic attached) and am moving on to two more Chevy projects, a 68 Chevelle for my wife and a 70 C20 for my daughter. I have a few questions for some of you experienced mechanics out there. See below:

1) My 72 Burb has a late 90s based 350 with Edelbrock RPM heads and an Edelbrock EPS manifold. Where the manifold meets the bllock at the front of the engine I used Black RTV per the manufacturers instructions. The area of the RTV keeps getting dirty/greasy and when I spoke to a friend he said that a small amount of engine oil is probably weeping from that area. I clean it off and 2000 miles later its all dirty and greasy again. Has anyone else experienced this?

2) I am about to rebuild a late 60s 307 and have been looking for some really good valves for the stock heads. They take a 1.720 intake and a 1.50 exhaust. Manley carries some severe duty valves that I would like to get but the 1.720 only comes in a +.100 length. Is it OK to use a +.100 length and should I get an exhaust valve that is also +.100 in length so that they are the same? Will I need to get longer pushrods? I plan on using roller rockers and a mild performance hydraulic camshaft.

Thanks,

Jeff

[krue]

No help on your questions, but that's a good looking 'burb.

[4x4Poet]

That's a gorgeous burb! The cowl hood looks better on it than I would have imagined.

On the RTV issue, just redo it. Let the new RTV set for 24hrs before starting engine. Other board members have said that RTV needs 24hrs to set hard enough to resist oil. You could also use The Right Stuff, instead. It's rubber based for a better seal but probably less heat resistence than black RTV. But the front of the intake has no need for a sealant with high heat resistence which is why black, vice red, RTV is OK there.

I like to use high quality FelPro intake gaskets with the *blue* sealing rings around the ports. I also use Gaskacinch on the gasket around the ports. Peals right off next disassembly.

[Yukon Jack]

What a beautiful Burb! Post some more pics if you can. I would agree that pulling the intake and resealing it is your option.

[Green Machine]

I think a nice upgrade for the 307 heads would be a 1.84 intake from a 80's something 305, gives you a new seat surface and if you back cut the intake it will flow better, You will likely need hardened seats put in the exhaust.