Engine block for my 68' Shelby

Need some opinions.

I notice an engine for sale that is the correct coded block for my Shelby GT500. The heads that are on the block are the incorrect 8 bolt heads.
I currently have a similar set up with the 8 bolt set up instead of the correct 14 bolt set up on my Shelby now and the block is a mid 60's block. My goal is to find a correct date code block (December 67') and heads for my car.

The block and heads that I am looking at buying come in as a package deal. Again, the block is matching for the month, but the heads are unfortunatley 8bolt. The machine work has already been completed.

Question, how often do correct code blocks/heads come up for sale? Also do you think that finding a correct era block would really increase the value of the car knowing that the engine is not correct anyway?

My car is just about 100% stock except for the darn non matching engine.

Suggestions?

thanks,
brian

 

Chris,
Thanks for your response. Would the correct heads be as hard to find as the correct block would be?

brian