ericmac450

I have a question.


My buddy has an old 305. (not sure of the exact year, but it's from the 70's) It is dying.

I have a 1989 Camaro RS with a fairly new 305. My Camaro has an automatic transmission. His truck has a manual transmission (3 speed is all I know about it) I want to give him my 305. Here is the question of the day however.

Will his flexplate for this manual transmission bolt up to my 1989 305?

I've heard the 1 piece rear main seal motors had to use a flexplate with a weight on it? If that's the case then I don't believe this swap will work, but please...can a reliable source shead some light on this whole subject.

I seem to remember hotrod magazine doing an article about all of this, however, I can't find the specific magazine and cannot find it on their website.

Thanks much,
Eric

Maverick H1L

iTrader: (8)

Chevy High Performance did the article you are referring to in the April '03 issue... I have it right here.

I read through it- If I've got this right, as long as you keep your engine and flywheel together in one piece, you won't have any problems. However, I don't know as to whether you would need a different flywheel/flexplate combo to bolt up to the manual transmission. The older engine has a two-piece RMS and yours has a one-piece. The article says that in addition to producing a smaller bolt pattern, the one piece RMS also requires an externally balanced flywheel/flexplate because the seal has to be round to keep the oil inside the engine, so the engineers were forced to remove the external balance weight on the end of the crank to accomodate the change in the seal. Also, the flywheel has a smaller bolt pattern which is .58 inches smaller than the older 2-piece RMS crank and requires a smaller bolt so the bolt can clear the rest of the crank flange. The bolts are available from GM and ARP (ARP P/N 200-2906 if you need a part number) if you need to change the flywheel or flexplate.

ericmac450

Your the freakin man! If I ever meet you I'll buy you a beer.


Ok, so the 1 piece rear main seal block used a different crankshaft bolt pattern. Now my only other question would be.


OK, my next question, if we buy a flywheel for a 1 piece rear main seal motor. Will that clutch bolt up to the newer model flywheel?

Maverick H1L

iTrader: (8)

I was busy adding to what I wrote before, but I don't like beer. But I'd take you up on one anyways.

ericmac450

Whatever kind of drink you would like I'll buy ya one.

Yeah, I had the article I just couldn't find it when looking earlier. I guess what we will need to do is just buy a flywheel (I have a flexplate on it now) for an 89 RS 305, install it, and see if the clutch will bolt up. I'm not sure exactly how a clutch bolts up to a flywheel to know if that will work.

The most myself or my buddy knows about the transmission is that it's an older GM 3 speed manual transmission. Probably from the 70's and probably from a truck. I am sure we can get something to work, I just don't know if we will be able to do this swap this weekend like we were wanting to.

If anyone has any insite on the clutch mating up to the new 305 flywheel then I'd be really excited, and greatful.

Stingraye

Ok, well here's the deal about the 70's blocks. I learned this one the hard way. 76 and prior had a staggered bolt pattern for the starter, therefore ONLY allowing the use of a 168 tooth flywheel/flexplate. so if he had that setup in his car, then his old clutch will not bolt up to a 153 flywheel as to the differnt size. However, if he originally had a 153 tooth flywheel on his car, and he gets a flywheel for a 1 peice rear main, then his clutch stuff will all bolt right on up. so just find that out and u'r good.

ericmac450

Thanks for your help!

-Eric