Untold thousands of 55-57 Chevy 265's got by with regular plugs and straight plug wire boots. They did have one bad problem- - - -the #7 plug was buried behind the steering gear shaft and it was very difficult to reach. I've encountered several of them 50-something years ago with 7 Champion plugs and one AC- - - -a flat rate mechanic had done a 7-plug tune-up at some time in the past! That elderly plug was always buried behind the steering column!

90 degree plug wire boots would give you a little extra frame rail or steering mast clearance- - - -use whichever works best for you.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!