I wouldnt expect a whole lot of performance gains going from the darts to the afr heads.

depends on what kind of Darts...so...what kind are they ?

Back to cams, what is your rpm at top speed ? And what is your compression ?

How much lift? Two years ago I built a 355" with Edelbrock E-Tec 200 heads and a hydraulic roller 230/238 on a 112 with .530 lift. If memory serves me I was either 11 or 12:1 compression. I ran Stainless Marine Exhaust. It made 425hp fully dressed with Stainless Marine exhaust on the dyno.

I went from turning 4800 rpm with the original 350 MPI to 5800 rpm with my new 355 MPI. If you want any info on the combo I'd be happy to dig it back up for you.
https://youtu.be/Pykm0boxvdE

PAnther - I remember commenting on your cam being a little too big back then, but I'm sure I didn't know you where running that much compression. WOW !

How much compression?

Jeff

That's what I remember because I think the stock CR is like 9.5:1. Add the extra cubes from the overbore and the flat top piston and I was somewhere around there with 64cc chambers. I could be off a little, I'm just going by memory.

I was afraid the cam was a little big and I thought the E-tec 200 heads were going to be a little big when I was building it but it all worked pretty well.

My Compression is 9.5:1 now and prop for a max RPM of 5800 - My existing Heads are Dart Sportsman II 202/160 ported and polished. I want to up my Compression by a point to 10.5:1 with the AFR Alum. Heads. My Rocker Ratio is 1.5 and again my existing Hyd Flat Tap Cam is 236 intake and 242 exhaust at .050 and the Lobe Separation is 112 - I think I can step it up a notch and I am reaching out for Selection Help. I don't get to a computer daily so please bare with me....

that is to much compression on pump gas

10.5 will be fine on a SBC but you'll just have to run 93. I would change to a hydraulic roller. The compression will make better use of all that duration.