Old Waylon on YouTube is building a custom 38 GMC truck with a V12. He’s been working on it for months and still has a ways to go. Some might find it interesting.
A friend had a 60 one ton panel with one of those V6s,he put too much oil in it and it spun a bearing so I got involved in changing the engine. Took a engine out of a cab over to put in it and found out after it was in that the water pump sat too high and would have been through the hood,he worked county fairs and loaded it to the max and it worked great for him.
My 305E is coming out this Fall even thou it runs great, starts every time. The 7mpg and 55mph is no more. Designed in 50s... for incredible durability and lugging capability, the low 7.5 cr helps lugging. Cooling system holds 32qts...virtually impossible to overheat with 170hp. The heads have similar ports to a 409... so poor mpg for both seems fitting. A stock CST 402 315hp BBC going in so I can drive on freeway.