The last thing I ever wanted to do was start another motor mount/ swap plate thread but I've been searching for 2 straight days and can't find answers to several questions. I currently have the original hooker swap plates (the ones they call "stock location" as well as the hooker supercomp ceramic long tubes for LS swaps into first gen camaro's (I have 68). I would like to use the headers if possible, not in a position to try to buy another set.
Questions....
1) When test fitting the engine I can get one mount bolt hole to line up but the other side is off by about half an inch. I remember numerous posts about this but the OP never really gave a conclusion on what they did to solve it. My first thought would be to elongate the hole? I'm going to try switching the plates left to right today as I saw mentioned by a few people but it doesn't look like this will work in my case with hooker plates. I confirmed last night with a tape measure that I do have the small block frame stands (2" to center of bolt hole on L, and 2-1/4" on the R)
2) Since I bought these plates (sadly 4 years ago and am just now mocking them up) Hooker now has 1/2", and 1-1/4" "forward" plates.... But I have had absolutely zero luck in finding anyone that has tried them. My dilemma is I have a harrop SC going on this LS2, so to get belt routing to work out I need to run the AC low on it's own belt. I ordered the S&P low mount AC bracket for LS3 accessories and a SD7 compressor so I think that is going to put me close but I am guessing I am going to need to pull the engine forward a bit so my frame notch doesn't go into the motor mount.
3) The real question to the last question is do the hooker 1/2" or 1-1/4" forward plates still work with their first gen swap headers? There is no mentioning on the Holley website either on whether they work with the headers. I left a message with tech last night so hopefully I get a call back today but was wondering if anyone had any experience with them.
4) Last question... I am using energy suspension motor mounts, they come with that spacer plate.... I found numerous posts where it was mentioned but nobody expanded on what they did, the pozzi website said they must be used but most pictures I have seen with adapter plates don't have them?? What is everyone doing with these? To get them to work I think I would have to cut/grind on the hooker plates... Any thoughts?

If the forward engine plates don't work with the headers I'm going to be trying the transdapt mounts because I know they will work with hookers and will move me forward about an inch or maybe go all out and try the dirtydingo.... OR.... stop all of this and just drill my own damn holes in the hooker plates...
I appreciate the help and once again, sorry for another thread about motor plates!

 

The mounts you have should work fine. I would unbolt the frame side mounts and bolt them to the motor mounts. Then set the motor in place where ever you want it to sit and either drill new holes for the frame side mounts or weld them in. This will allow you to also move the motor forward or back a bit where it works best for your headers and fitment issues. Make sure you have a pan on the motor when doing this to check for those fitment issues as well.