whos runnin dirty dingos on 63-66

[pete57]

Im needing some help, I gotta '64 c10 i put a 5.3/4l60e in. I used the dirty dingo sliders mounts and running the doug thorley long tube headers. Ive read where a few people on here are using this set up with no issues.MY issue is with engine slid all the way forward my headers are hitting the firewall before i can get my 3 degree rake for driveline angle, sitting at 6* now with headers on firewall measuring from top of intake. Any body else have this problem or any ideas. Only thing i can see is to maybe move factory perches forward an inch or so. Would like to keep my headers off the fire wall. Been a pretty simple swap so far, 1st problem ive ran into.. Thanks.