I think the engine cores would be a problem . Trying to get good used cores to build up . Or if you use all new blocks this will bring up the co$t . I do think one way around this is a base engine like the Chevy LM1 350 . This engine is like $1400.00 buck for the long block . Most guy wont want to run the #993 76cc heads That are on it . But you can removed and sell them as stock replacement heads online . Also the new cam and lifters can be sold this way . Now you have a 4 bolt short block with the tin . This short block has LT1 powdered metal rods that you can build up with ARP bolts . Then change the cast pistons with hypereutectic flat tops . Then for heads go with the #1 selling Vortec heads . Set up the heads to handle up to 525 lift . Then give the customers there choice of cams intakes and carbs dist . This is an idea for a street/strip all new SB chevy . With the right cam this set up will make 400HP .