what is the difference between Academy's and Tamiya's M51 Super Sherman? A guy at a local hobby shop told me the difference is that Academy's is a later version than the tamiya one I do notice they have differnt rear engine decks can any one shed some light on that

Tamiya's is perfect for '67, and I think up until about 1970 or so. If I recall, Academy's is good for post '73, and by that I mean not for '73 itself. The exhaust and louvers on the engine deck are the biggest differences. Academy's also has a mortar in the turret roof - not correct for '67.
The Academy rear hull plate is also space out further and needs to be be re-angled and repositioned to be correct for earlier variants. The large stowage basket at the rear was also for later variants. Tamiya's M=51 has the old "folding shelf" on the rear, again correct for '67.

So if I wanted to do a Super Sherman from the 73 war I would need to use the upper rear engine deck from the Academy and put it on the Tamiya?

If you have the Academy kit, you'd have to reposition the rear plate, remove the exhaust from the engine deck, (and add to the hull rear)and replace the louver detail you've destroyed in the process. You may also want to totally reshape the front hull.
For the Tamiya kit your options are simpler - get the Legend 1973 M51 conversion. Even so, it's not quite correct for '73. You have to remove the exhaust and replace it with one coming out of the rear hull. Then get that M51 stowage set I reviewed a few weeks ago. Awesome set.

Hi,
One thing I would add is that the muzzle break on Academy's kit is WAY too big.

I've got both kits and Academy's kit is about twice the size of Tamiya's. Accurate Armour do a good update to fix this as which also provides both engine decks.

Thanks,
James

There were 3 different types of the muzzle brakes for the M51. It can get kind of confusing. Also, SuperSherman is a misnomer..... the only supershermans were the M1A1 armed M4s. M50 and M51 were just that...

Chris

IMHO, the Academy kit is way below standard, even when it first came out. It and the Dragon version were meant to represent a very late version, but each have major flaws. The Tamiya kit is perfect in scale and detail, OOB for '67. (The hollow bogey units are easily fixed, and that was done to simply casting.) For '73, the easiest upgrade, cost aside, is to use the Accurate Armour conversion. It's engine deck is reversible by just flipping it over, plain for '67 and with louvres for '73. A nother option is to use a spare Dragon deck and just cut the top exhaust shroud out and replace it with the flat piece. The Academy deck's louvres are out of scale. Frankly, it really isn't that much work to scratch-build the louvres right into the Tamiya deck. I'm aware of only two versions of the muzzle brake, with and without the horizontal braces. Photos of a third type (my stuff is all packed up for a house move) are always welcome. The Tamiya kit stowage is perfectly adequate for '73, although you can also do the version in the Academy and Dragon kits. The Super Sherman name is applicable only to M4A1(76)HVSS versions with the M1A2 gun. The other 76mm versions, either M4A1 or M4A3, regardless of gun, all VVSS, are known simply as M-1, as are M-50s and M-51s. Again, just one man's opinions.
Tom

One of the Manasherob M51 books has a few pages of photos dedicated to solely to the three types. No access to it now though.