I really hate oil leaks – and I have chased a few. The chrome front covers can be problematic especially those made in the past ten years or so as they’re made in China and the quality control is nonexistent. As nice as the chrome pieces can look - I really shy away from them as they can be more problems than they're ever worth. I like the stock pieces as they've been designed to work well. A good cleaning and a couple coats of Chevy orange makes them look as good as new.

Since you don't have the original metal, it may be best to back up and replace both the front cover and the pan with new first tier products. I like Milodon and have had very good success with their metal products on multiple small block builds. I’d recommend the following parts:

Front cover 65555 - http://www.summitracing.com/parts/mi...-size/5-7l-350

Front cover gasket kit - http://www.summitracing.com/parts/mil-65503/overview/

Stock replacement pan 30700 - http://www.summitracing.com/parts/mil-30700/overview/

Pan Gasket - http://www.summitracing.com/parts/mil-41000

This pan gasket has a thick front seal that is required for a nice tight fit with this pan. Most people don’t know that there are two different pans for small blocks, one measures 2-1/4” from the pan rail to the lowest point of the front opening and the other measures 2-3/8”. You can have real problems if you use the wrong gasket here.

I like this stud kit, but it’s not necessary, 81300 - http://www.summitracing.com/parts/mil-81300/overview/

Start by draining the oil and taking all the front end stuff off. Clean all the bolt holes and run a bottoming tap down each one to clean the threads. Blow out the holes with compressed air. Remove the pan and clean everything with lacquer thinner or acetone (use safety glasses and a cotton disposable respirator – trust me here). Wipe everything down with soft cotton rags and then wait a half hour and repeat to make sure you get all the dribbles.

Press you new seal in the front cover and apply a thin layer of grease. I'd use Permatex Ultra Black or Gaskacinch on the front cover-to-block gaskets. Use a thin bead on the cover and the block and press the gasket into the sealer and assemble without letting the sealer set too long as it needs to adhere to all surfaces. Don’t over tighten! 5-6 ft/pounds is what you want here – no more! Most leaks that I have encountered are a result of someone tightening these bolts way too tight and distorting the metal to a point of no being able to ever properly seal again.

The one piece gasket snaps into the pan for proper alignment and has inserts in the holes that help prevent over tightening. Put this gasket on dry. The Milodon pan has nice thick rails and will pull down against the thick front seal to the timing cover. If you have a helper here it is great to have him hold the pan in place while you start the four corners. Get all the bolts started and tighten the pan to 12 ft/pounds. Again - don't over tighten these bolts.

I know it is pain to do this while the engine is in the car – but it can be done successfully

Good luck here – you need to catch a break on this one!
Glenn