Where is a good source for various sizes and angles of the clamped rubber elbows and straight pipe sections like commonly used under the hood of a class 8 truck? I have a couple of custom air intake hoses that are NLA but could be reworked with the right parts. Somewhat smaller than a 14 liter engine, though.
Something like this? https://www.aemintakes.com/diy-bent-aluminum-tubes.htm Most of the racing /adding turbo /intake custom stuff I see is just welded up.
Donaldson https://www.donaldson.com/en-us/engine/filters/products/air-intake/accessories/general/
www.siliconeintakes.com is where I've purchased numerous intake components and clamps. Not sure what their cut-off size is for big stuff but they had everything I needed when I was working on a JD 4045 and some other engine components for larger engines. Reasonable prices and spiffy colors too!