Advice needed on 427 block

[MrBuffet]

Hi all,

I'm basically a few days away from pulling the trigger on my roadster build, and I've reached the last decision point on my engine -- I have access to 2 427 blocks, and I need a bit of insight as to which one to pick...

Now regardless of which block I chose, there is a long list of parts which would be the same regardless of block choice, so let me just give a rundown of those;

- Original crank ground 10/10, magna fluxed, nitrated and cross drilled
- Original heads with factory adjustable rockers
- Original factory flywheel.
- Original Factory rods reconditioned with ARP bolts (De-beamed magna fluxed and nitrated)
- New "Original" cam (replica of mid-1960 ford race cam)
- New cam bearings
- New double roller chain
- New rod and main bearings
- New rings
- New gaskets
- New dampener
- New pushrods
- New Edelbrock intake manifold (Performer RPM)
- New lifters
- New springs

Now -- there are differences, and those are;

Contender 1 is a 1965 C6AE-C, 5J8 date stamp. It is cast as a side oiler, but drilled as a top oiler, it has been bored 0.020 over, however 2 of the cylinders have been sleeved -- the block has then been magna-fluxed and is in good shape. It is currently in short-block form, hence the piston choice was already made and it is Keith Black 11:1 flat pistons.

Contender 2 is a 1965 C5AE-A marine block, 5C12 date stamp, with less that 500 hours on it, no cracks. It is (obviously) cast as a top oiler, it has yet to be bored, and I could potentially get away with not boring it at all, but to clean it up really nicely would mean 0.020 over. the good news is that all cylinders are in great shape. It is currently in bare-block form, hence I can chose whatever pistons I prefer.

So here comes the big question -- which block to chose? --

- I'm hearing mixed views on trying to re-drill contender one to a side-oiler (especially because of the sleeving), any thoughts on that? has someone here actually tried to re-drill a top-oiler?
- I'm also hearing "buyer beware" on marine engines, as some say they were blocks that failed QA, and got deemed only useable for lower RPM duties. are some marine engines ok to use? what to look for?
- As this is supposed to be a everyday street driver, with no drag or strip (and I really do not want to deal with octane enhancer or race fuel) I'm hearing that 11:1 compression is pushing it for pump gas, and that 10:1 is pretty much the top with cast heads. Can someone confirm or deny this?
- In all reality what kind of extra value (outside bragging rights) would I get out of a side-oiler vs. a top-oiler?

Any advice / input would be greatly appreciated...

Thanks,

Peter