The ls and the sbf have near identical cylinder spacing, I often use LS fuel rails on the sbf with aftermarket intakes as they are cheaper.
Honestly the LS is an amazing platform and I see no benefit from making this work... Just get a 4.8 or 5.3 out of the jy and drop it in.
Honestly the LS is an amazing platform and I see no benefit from making this work... Just get a 4.8 or 5.3 out of the jy and drop it in.