Cylinder head upgrade for my SB400

[Rich69shortfleet]

Many years ago when I built the drivetrain for my '69 C10 I considered going big block but the costs scared me away. The truck was originally a small block truck so I would have needed everything including brackets, etc. which gets pricey. Anyway, I'm more of a small block guy anyway so I went with a '76 SB400 out of a '76 Blazer. I installed 5.7 rods and built a really nice just-a-notch-above-stock engine. The primary role of the truck was to be a nice driver and workhorse so I didn't want to hot rod it. It ended up with a Crower Baja Beast flat tappet cam:

Lift: .414 - I / .417 - E
Full duration 258/264
Duration at .050 204/208
Lobe separation 112

It idles pretty smooth and has a lot of low end grunt, pretty much done by 4500 RPMs though. Power runs through a TH350 with a mild shift kit and a 12-bolt truck posi with 3.73 gears. I've always thought a more modern auto with overdrive would be nice but I've never pulled the trigger on that. I retained the original tiny valve heads, just a 1.76 intake, but I did later upgrade the intake manifold to an Edlebrock Performer Q-Jet. The original quadrajet was used but slightly modified to run better than in it's original smogger motor configuration. Carb works excellently. The ignition is stock HEI with better advance weights for a more aggressive curve, 36 degrees all in by 2800 RPMs. I used the stock rams horn exhaust manifolds down to 2-1/4 dual exhaust with no crossover. I originally had a crossover downstream but it made working on some things tough and caused a broken exhaust manifold since the system wouldn't really rock with the engine. It has about 38k on the rebuild. Runs fantastic.

BUT, I'm bored. I've been wondering how it would do with much better heads. I've become a fan of AFR Enforcer heads and was thinking of adding these to the mix: https://www.summitracing.com/parts/afr-1011ft

They are as-cast aluminum heads with 2.02/1.60 valves. Would certainly improve breathing. Might cause the compression to go up as the smogger heads I have probably have a 76cc or larger combustion chamber and the AFR ones have 64cc chambers. I roughly calculate the current set up is running about 10:1 compression. I pretty much have to run 91 octane gas or I have to really back off the timing and it will still knock under load.

But I wonder if the heads would be a waste with such a mild cam. I could upgrade the cam too, but I still want the truck to pull and haul well and remain super reliable as it has been.