What size red 6?

I'm no red 6 fan and far from an expert. My advice would normally be to pull it out and replace with a V8!

But a few things I've learnt over the years:

Blue/black 3.3 crank and rods, just need a rope seal 202 block.
Red head, look for an old Yella Terra if you want it to look like a red engine. Find an old 186S intake and carby or use a Ford Weber 2BBL or modded 253 carby. Just use the 186S exhaust manifolds or extractors with a single 2 or 2.25" exhaust.
HEI dizzy off a blue or EFI black engine.
Talk to a cam manufacturer for a cam to suit your needs.

Better still use a whole blue or black engine. Buy a Perfectune new head for it or modify the original, rest similar to a red except not sure what intake manifold options you have. Redline make a 4BBL to blue/black, but you'd want to be looking for a very small 4BBL like a 390 Holley. You can buy these new from Holley with vacuum secondaries and electric choke. https://www.holley.com/p...sic_holley/parts/0-8007
Not sure what extractors are available for blue engines in all shape Holdens.

There are other methods too, like building a 235ci stroker, or even fitting a whole EFI VK engine with an ECU conversion from a VN V6.

Or other similar stuff from fitting a 292ci Chev 6 (will fit straight into HD-WB using the right sump and a TH350 box as this was done for South African examples of these cars) - you won't get much torquier than these! Or even a VN onwards V6 conversion.

Thanks for the tips fellas.You've given me some good ideas.As for the jetting my car seems to gain about 10 horse power at night.Must be that good oxygen in the air that my holley is sucking in.

Air is denser at night because it's cooler. Therefore more power potential.

Whilst EFI cars adjust the mixture (either from the pre-defined fuel map under acceleration & load, or from closed-loop feedback on lean cruise), the main reason for consistent power with EFI is that almost without exception, they all have some form of cold air intake, drawing air from outside the engine bay - either from beside the radiator, over it, in front of it, or from under/around the headlight area (in passenger cars & derivatives - you could add snorkels for 4WDs).

With a carby car & a traditional air cleaner, the engine bay temps can easily be 60-70 degrees on a warm day - and that's the air the engine is ingesting, rather than 25 or 30 degree air from outside the engine bay, fed via a cold air intake. Years ago I did the measurements with a wired probe on a digital thermometer inside the air cleaner housing on a VH 5L
I had a VK Brock cold-air pipe & air cleaner on it, and wondered if the pipe was worth it. The results were startling - only a few degrees above ambient with the cold air pipe when driving at 60km/h, but some 30-40 above ambient without it. It was far worse when idling in traffic. Idling also increased the temp in the air filter housing with the cold air, but as soon as you got moving it dropped back down quickly.