The customer is always right. Uninformed, hard-headed, stubborn yes, but still always right.
Good call on your part for having your client purchase the crate motor that HE wants. Its all on him now.
Well, the customer is always right, that can be true, but sometimes a customer will go to a pro because he does not know, he expects info and he wants to learn... A 327 in that truck is indeed a funny idea, but maybe this customer wants a 327 because he had 1 in high school (in a Nova), or his parents' station wagon had 1 when he was a kid. Maybe someone needs to tell him that any small block can be made to look like a 327 (with the right stickers!), maybe he is the kind of guy who just does not know and who needs to hear about options, to hear that GM sells an excellent 383 crate engine that would suit him much better (if he wants a GM crate)!
Because the risk here is also a customer who ends up not happy and blaming the shop for not steering him in the right direction...