RPM red line for STD A7 engine ?

[Alan]

The limiting factor with a standard engine in good condition is probably the con rods. Some standard rods are good for more than5000 revs, but not all are, and as you won’t know until it lets go 4800 is a reasonable limit. I know others will claim more, but engine rebuilds are expensive. However, I don’t obsess over much with engine speeds. It’s the shape of the power curve that matters. With a standard engine at 4800 you are probably on the falling part of the curve anyway, so there’s not much point in being there unless you are trying to save a gearchange on the last 100 yards of a finishing straight. And, if that’s the case why are you on a standard engine.
On the other hand a properly built, forged crank and rods, balanced,etc race engine will see 7000 regularly, and more on aforesaid finish straight.