Don't think so, but not sure. Were the 243s on the last motor shaved? I could have sworn you did the TBSS intake to this and had it dyno'd or something after the 243s, but you'd know better than me if I'm full of crap or just confusing your builds.
I believe you're thinking of my 1990 RCSB, with a 6.0 that has 243 heads, cam and a TBSS intake manifold.
This burb did have a TBSS intake temporarily.