texas jim

Is anyone using the GMPP Vortec heads w/ the 2.00/1.55 that also accepts the old 6 bolt intake/valve covers?

gdh

They came on the ZZ383 Deluxe that we dropped in 2 summers ago. What would you like to know?

texas jim

. Do you think these heads are worth buying for a 355 ci build or should I go with the regular small Vortec heads? I have an Edelbrock rpm air gap and my original 1981 valve covers that I would have to replace with the regular Vortec heads, more cost.

GAVelle

On my 1969 I have the iron Bowtie Vortec heads (which have larger valves, screw-in studs, stainless valves with sodium-filled exhaust valves, and permit lift up to 0.530" compared to regular Vortec heads) that I think you are referring to. I have a Vortec-specific intake. (Supposedly, although the bolt pattern matches the regular manifold, the ports are raised on Vortec heads and thus the ports on a standard manifold may not match up with the ports on the heads and may result in vacuum leaks.) I never experimented with trying a standard manifold, but the CPP catalogue does not say that a standard manifold will work.

But, I use the original, standard steel painted valve covers for an original look. Also, I have to use a drop-base air cleaner base with a shorter filter to clear the hood. I think the smaller filter reduces air flow at high RPM.

If I were to do it over again, I would use high-flow standard heads so that everything fits better unless I had a hood with more clearance. If your car has more clearance than a 68-72 small block hood, then the 185cc iron Bowtie Vortecs, compared to standard iron Vortecs, would be nice because of the increased valve lift capability, the nicer, and larger valves and springs, the ability to use stock valve covers, and possibly the ability to use a standard intake if you can avoid leaks.

gdh

I'd make sure that the larger heads would bolt on first. There's not a lot you can do to these heads for additional performance ie. porting. I'm happy with the engine as it suits my needs and I got it for a fantastic price. For your engine I would look at AFR 180's or 195's over the Votecs if you can get them at a good price.