Thanks again for all the info! I do hope you decide to stick around for a while.

With the 6M I'm sure you meant it's a 5M with a 6M crank... even the 7M ran a 6M until '89.

No i meant exactly what i said.. A 6m is a 5m with a 7m crank and different timing gear.. The crank in a 7m is just that a 7m crank.Yes it is shared by the 6m but the 6m has the 5m head.. The blocks on the M series motors all share the same blocks regadless of displacment.. Even the 2.0 2m made in 1965..No difference.. All that toyota did was enlarge the bore and stroke over the years aswell as head design .. Sure you could say that the 7m had a 6m crank in it but they are the same through and through.. Just the heads were changed along with the pistons because the 5&6m's had 2 valve releifs and the 7m's use 4 valve releifs.. Try to run a 5m head on 7m pistons and your going to bend every valve, same goes for the 7m.. Ive been here for awhile i broke my laptop and havent been on for a smooth minute but ill be checking in more often now.. I have learned so much about these cars inside and out that i get a hard on seeing one driving down the road and cry when there is one in the salvage yard..

I'm just talking about the cranks. Open up a pre89 7M and you'll find a 6M crank... in the '89 and later 7M's you'll find a crank that is actually stamped 7M, has a very hefty bump in rotating mass causing a 250RPM reduction in redline. I'm just surprised to learn that they used the 7M crank in another engine so long before.

Glad you're back. I felt bad letting a lot of stuff go without answers here and have been sending a lot of PM's suggesting that really big Celical Supra site.

the 2000 gt is pretty much wat started it all for the supras. i know everything is compatible if u change the interals u need to change the head because 1 is 12 and other is 24 valve. the blocks are excactly the same with dif internals evu erything is interchangable and from experince u do not have to grind it down to make the header work loosen the bolts remove 1 thats .closest to the header push it forward and its good dnt waiste ur time grinding it down. ive done alot of research on this stuff. dnt be a dick to the adm. he was just tryn to get more info for the ppl that dnt have a clue wat their doing

Not being a dick just trying to educate.. Yes the cranks were from the 6m but now adays and espeacially here in the US a 6m is hard to find considering they werent available here.. Ill give him that it did increase higher RPM and can be used as a power increase for less rotating mass but the 7m cranks are alot more plentifull.. Anyway you slice it they are still basiclly the same..

Likewise... and learn.

You're wrong there; It was the only crank used in the earlier 7M. The 7M crank didn't see a 7M until after the '88 production year (a bit after '89 actually). 86.5 through the middle of '89 p/n: 13411-42030. The 7M crank was used from the middle of '89 on p/n: 13411-42040. In '89 the tach's gauge face was changed to reflect the new redline, although some '89's still had the 6M crank and could be safely revved higher if not for the lowered limit in the ECU.

There's a lot of info about this throughout the Supra community as people like to debate which they should run in their build. My '88's got a 6M and I'm certain it's not a JDM swap. My friend's '88 has a 6M, his '90 has a 7M. I know plenty of people with 6Ms, they're all pre89s.

Here's a great comparison: http://www.jblmk3.com/cars/crank_comparisons.php

Ok i stand corrected.. That was a great link.. Im adding the files to my collection right now.. I have never seen this kind of comparison done and was very insightfull.. Thanks and i apollogize if a offended anyone..

No need for any apologies... and yes, it's a very well done comparison. I'd like to see one done of some of the other common and interchangeable components.