Stock heads/rotating assembly, hot cam/vlave springs- how far can you go?
I prefer to use my car for general backroad hooligan driving so I really want a motor that breathes and feels relatively happy revving out upper 5ks at least.
I just wanna say this
Backroad hooligan driving used to be my passion too. But I kept it below 50 mph, cuz our ditches are often,mostly; deep and steep; And I know what a sudden stop feels like at 30 so I wasn't interested in finding out anything more than 50.
That said, my backroads are gravel, and I had 3.55s with a 4-speed. So for me 50=4200,40=3360. So for me, power at 5500 didn't mean spit.
But for you with 4.10s and a 1.45 second gear , 50=3900 @5% slip, even 60=4650@5% slip, so again, power at 5500 don't mean spit.
Those 4.10s will hit 5500 at about 71 mph. So if you're blasting gravel backroads at 70 plus mph , you're either waaay braver than I ever was, or IDK what either,lol.
But on hardtop, Ok I concede the point.... but then the question is; how long are you expecting your engine to last, blasting at 5500?
I did that one time, and said goodbye to #1 rod bearing. Another time #3 went out.
Have you done any oiling mods to her?
You know a 318LA-2bbl cam will rev to upper 5000s right. It just takes the complimentary valve gear. I mean it won't make much power up there, but it will rev to there.
Be careful what you wish for; Rumble posted a well-thought-out answer.