Yea, the motor & trans mounts themselves keep the engine where it should be.
NOT using the stock engine & trans mounts normally requires a motor plate &/or mid plate with a fabricated trans mount.
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Ok. I was curious about this as I've started a 68 Dart build, RB block and will be using an engine plate. Want to run at least a 26 to 27" front tire. Want to go with fenderwell headers and wondering what would need to be modified to get the motor back enough. I haven't purchased headers yet.