1966 C20 5.3 swap. What motor mounts?

[Mathew21]

I'm here in Michigan waiting for winter to end so I can attempt to do my first engine swap. I have been collecting parts to do a 5.3/4l60E from a 2005 silverado in my 1966 C20 that currently has the original 327 and a 700r4.

What motor mounts should I buy. I thought I read to go with clam style mounts with dirty dingo sliders. Does that sound right? I have no plans on running A/C. I already bought trailblazer ss exhaust manifolds. If you have a any suggestions I would love to hear them. Also if you know the part #'s of what you suggest that would be awesome.

Thanks, Matt

[68c10airstream]

Hi Matt, If you ever want to lower it and/or run headers, the oil pan depth and frame brackets sourced from aftermarket will get in the way with stock motor mounts. I suggest 98-02 f body mounts and the associated cast brackets that attach to the ls engine. You will then have to make a simple adapter plate to attach to your cross member down low out of the way of all future potential issues. Some old style motor mounts can separate and the motor flop around in the engine bay like a fish out of water. Good quality mounts are what i call encapsulated. If they separate the motor can't move but just a little bit and not hurt anything. Oem mounts from the 70's on up are this way. I hate rock hard mounts so i suggested late model mounts. Gm engineers want to control what they call noise vibration and harshness. Late model pickups are as smooth as cars now, so benefit from all of their hard work. Also the 98-02 f body oil pan is really low profile in all areas. I did all of the above when i installed a 5.3 in my 68c10 and don't regret it a bit. I suspect my way isn't the most popular, but my engine is as low as possible, oil pan isn't sitting below the cross member, and the engine feels smooth. I know your initial question was mounts but i ran with it. Ebay, etc, will have everything you need. Good luck, Brian F. from the U.P.

[Mathew21]

Thank for the information Brian. My truck has 2" lowering springs and 2.5" drop spindles. I did buy a F body oil pan to help with clearance issues. With the roads here in L.P. I can't take a chance with the oil pan below the crossmember.