440 in an A Body?

I have a 71 Demon with a 69 440 & TTI headers with the Shumaker mounts on a 340 K-frame. I knew it was going to be tight but everything seemed to be ok until recently. I drove it twice locally last season and after driving it a couple months this season I have noticed some problems.
1. the Black Aluminum Mopar valve covers leaked a little (I found out they were cracked ) so I replaced them with a chrome set (given to me) and they were worse they gushed all over everything.
2. I also noticed (while cleaning the oil) that my steering center link is hitting the oil pan and denting it & might wear through soon and the nut from the pitman arm is wearing a groove into one of the header pipes.
Question: What is a good way to seal valve covers to keep from making a mess?
Is there a certain Center Link/Pitman Arm/Idler Arm I need to use or do I need to raise the motor?
Any help would be greatly appreciated.
Thanks Angel Cancel I can be reached at [email protected]