Engine Mount Question

[joesscamaro]

Hello all! I have a question I'm ashamed to even have to ask, but here I am. I've got a '65 that I'm putting an LS1 and 4l60e in. I'm using the Dirty Dingo slider mounts and I feel like I've read in my searchings that I can use my original engine perches (SBC V8) and the rubber engine mounts from the same SBC V8. I must be reading something wrong because I can't get the bolt holes in the perches to line up with the forward 2 holes in the frame. I know I have to drill a new hole in the crossmember. It just seems like the engine perches are too wide to line up with the holes in the frame. I can get two bolts in on one side but then I'm fighting to even be able to get one bolt in on the other side. It just seems like they are too wide for the existing forward holes in the frame. Any input? I did just read on Dirty Dingo's site that they recommend the 67-72 V8 perches. Does this sound right?

[joesscamaro]

Pictures for reference.

[mongocanfly]

Think those are meant for clamshell mounts arnt they?
My clamshells lined up perfect on my 81....not sure about a 65
Does the ls1 mount the same as a lm7 5.3?

[joesscamaro]

Mongo: I'm not sure about the mounting location for the 5.3 vice the 5.7. I have been doing some reading and from what I can tell, to use the forward mounting holes would require the I6 292 engine perches...which are evidentally very hard to come by. I think I'm just going to order an aftermarket perch/mount kit that will work with the DD mounts.