I just got caught up on your build, its great to see you working on it again. Its looking awesome, engine block and pan black, heads and intake natural allum or paint allum as close to natural color as you can find.
For a good aluminum look you can try Duplicolor aluminum paint. I sprayed the case of my T56 with it. It matched the new OE bellhousing I bought very well. My only complaint is it has just a little bit too much sheen when it's fresh. It loses the sheen over time or at least the LT1 intake that was on my last engine did - it ends up looking very natural.
Depends if you plan on keeping the car the same color. With the frame, firewall, inner fenders being a dark color. The engine being black it will disappear. If everything around it is dark it should be light in my opinion.*
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1969 Camaro LS2/T56 D1SC www.automotivedesigneng.com
Special thanks to: DPE Wheel / Columbia Parts Company / US Collision / T. Bruning
Thanks again guys for all the great input! I never really liked the color differance of the silver...it was sold as an aluminum color paint but turned out bright silver. Oh well, no biggie!