It's your truck, so paint as you want. However, if you want to look "original," here is some info ...

> Stovebolt thread with similar question and answers.

Painted engines on 1947 engine line from "Pictorial History of Chevrolet 1940-54" posted by Pre '68 Dave (in the thread)
> 1947 Assembly Line
> Close up #1
> Close up #2

> Tim Lederman's recap of engine paint.

> 1954 engine shown in "1954 TRUCK ENGINEERING FEATURES"

The Chevrolet script on the top of the valve cover was painted the same as the valve cover.

> Location of '54 valve cover decal

As Don noted, intake and exhaust manifolds were painted the same color as the engine. Exhaust paint burned off as the engine was run.
> I use Calyx on my exhaust manifold.

Here is the 235 in my '54 3104. Not saying that it's a faithful reproduction, but I tried.
> Passenger side
> Drivers side and manifolds
> Drivers side high

- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

OLD STUFF ... houses, furniture, cars, wine ... I love it all