Not sure about ZZ4, but they fit a small block in G body really well. Good access to remove starter without removing header and good oil filter access. Only had to grind a little on the passenger lower control arm mount. Very minor. My Dad had Hedmans and they were a complete nightmare. Poor oil filter access and had to loosen the header to install the starter.
I used Hedman shorty headers on the 350/330 crate motor that I put in my wagon. Plenty of room for the filter and starter but the left side is really close to the transmission. So close I cant put the convertor/flex plate cover on.
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