solid motor mounts/motor plate

[68pont455]

anyone used solid motor mounts on a 455 in a 67-69 firebird. i have been told that the block would crack at the pan rails. i was also told that motor plates bolted to the heads would cause head gasket sealing problems. motor plate should be attached to the front cover mounting but i have a moon cover with a cam driven fuel pump so its not feasible for that set up due to balancer clearance to the cover and the way it mounts. what is anyone else using out there?

there are a couple of suppliers of motor plates that work great if you use a stock front cover and water pump. cannot do due to above.

i have also heard the best way to mount a front plate is between the timing cover and the block. then just machine the cover the thickness of the plate. that sounds like the best bet. let me know what you think.

[bubba428]

I would just use heavy poly bushings

[68pont455]

do they make them for my combination. never seen them.

[johnjzjz]

people who know nothing will tell you the stupidest things - pulling the side of the block off is a real worry has happened to me - big power to do that and lots of frame twist needed as well left wheel off the ground 2 feet right wheel still on the ground - does you car do that ???????

front motor plate causing head gasket leaks -- same thing frame twist needed

most plates end up part of the timing cover and front block attachment holes for accessory's than attach to the chassis side rails to welded stays

i like the use of a mid plate ( between motor and trans ) to welded tabs on frame rails and stock solid mounts this way no travel limiter bar is needed ( limit bar stops motor from front to rear movement ) when using a front and rear motor plate together - Caution mid plate moves converter for trans out so washers needed to shim it so only .100 movement from pump to flywheel - write that down if you do that you will have to make sure the snout on conv is in the pump gears correctly --

front steel solid mounts stock position and mid plate ( ALLOY or steel ) both being solid if you run a glide you do not need a trans mount at all, but if its a 3 speed you will need a stock soft rubber mount ( NO SOLID NO POLLY ) or the bell housing will crack on trans and the mount holes need to drop directly over onto the mount no tweaking or things will crack it is simple just follow the correct way to do it -- jz

[1QWIKBIRD]

My buddy uses the front motor plate itself as the mount for his vacuum pump. I am sure you could do the same with an alternator. You would need access to a bridgeport or something similar to machine the adjustment slot into the plate, but it should work. Run a mandrel on the crank snout and then shim the pullies until they are in alignment. This is on a race car with a SBC, but it works just fine for the vacuum pump. Might be worth considering???

[68pont455]

Originally Posted by johnjzjz

people who know nothing will tell you the stupidest things - pulling the side of the block off is a real worry has happened to me - big power to do that and lots of frame twist needed as well left wheel off the ground 2 feet right wheel still on the ground - does you car do that ???????

front motor plate causing head gasket leaks -- same thing frame twist needed

most plates end up part of the timing cover and front block attachment holes for accessory's than attach to the chassis side rails to welded stays

i like the use of a mid plate ( between motor and trans ) to welded tabs on frame rails and stock solid mounts this way no travel limiter bar is needed ( limit bar stops motor from front to rear movement ) when using a front and rear motor plate together - Caution mid plate moves converter for trans out so washers needed to shim it so only .100 movement from pump to flywheel - write that down if you do that you will have to make sure the snout on conv is in the pump gears correctly --

front steel solid mounts stock position and mid plate ( ALLOY or steel ) both being solid if you run a glide you do not need a trans mount at all, but if its a 3 speed you will need a stock soft rubber mount ( NO SOLID NO POLLY ) or the bell housing will crack on trans and the mount holes need to drop directly over onto the mount no tweaking or things will crack it is simple just follow the correct way to do it -- jz

i have had the car launch a foot or so up but it doesnt twist much. pictures show front and rear of car is level on launch. i have a full cage which helps considerably with that. also back half is supported properly with good shocks and springs and properly adjusted 4 link.
thanks for the input