How long is a piece of string?
I assume this question is aimed at Mace Engineering (which is nothing to do with me) but you need to be much more specific?
What condition is the engine in now, is it running or completely ceased? How many kms has it done? Has it ever been overheated or leaned-out? Does it only run on petrol or LPG?
What are you aiming for, a drag/race engine, street performance, towing, el stocko daily driver?
How much of the work can you do yourself, R&R engine etc.? (And probably a hundred other questions?)
If you're specifically looking to get Mace Engineering to do the job then I'd suggest giving them a ring.
Andrew