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NV4500 to 327 Qs

CUCV2

CUCV2

5/4 ton fun
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Just picked up a 99 version of the NV4500 to put behind a 1966 Impala 327 engine that is going into a 1959 GMC. I have a clutch set up for an SM465 and was wondering if that would work in it? The clutch disc has the right spline count. Is the internal spacing correct though? Also, this has internal slave cylinder with the o ring fittings. I've heard it can be problematic with leaks. Is there a correction for this other than an AA bell or should I fork out the $ for the bell? Thanks in advance.

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The 465 clutch won't work with a internal slave 4500. Pressure plate is different.

As far as the o ring fittings it's pretty easy to swap them out for AN fittings and hose. Which would be helpful in your case because it's unlikely to make a stock clutch master cylinder work with the '59 pedal.
 
ZooMad75 said:
The 465 clutch won't work with a internal slave 4500. Pressure plate is different.

As far as the o ring fittings it's pretty easy to swap them out for AN fittings and hose. Which would be helpful in your case because it's unlikely to make a stock clutch master cylinder work with the '59 pedal.
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Thanks for the reply. I should have mentioned that the 59 will be using a hanging pedal conversion from Classic Performance Parts that uses a hydraulic master cylinder. I'm waiting for it's arrival as we speak. Would the best thing to do be to order a flywheel and clutch from the same year truck as the donor transmission or can I use the SM465 flywheel at least? I'm unclear as to the internal or external balancing issue when putting the older engine with a newer transmission. Should I use the flywheel meant for the engine or the transmission. Thanks.
 
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Flywheel should work fine. But get the clutch for the year and model of truck the trans came from.
 
CUCV2 said:
Thanks for the reply. I should have mentioned that the 59 will be using a hanging pedal conversion from Classic Performance Parts that uses a hydraulic master cylinder. I'm waiting for it's arrival as we speak. Would the best thing to do is to order a flywheel and clutch from the same year truck as the donor transmission or can I use the SM465 flywheel at least?
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Thanks for the quick reply. I was actually editing my response when you posted to include a question about internal vs. external balancing as to what flywheel should be used. Just want to get the details right so I can hopefully get it right the first time.
 
Most of the time a 4500 is going to use a 11" or 12" clutch. As long as the 327 flywheel can take that big of clutch (which it should) you should be ok.
 
As far as I can tell, the small block two piece rear mains flywheels are all either 153 or 168 tooth. The confusion seems to stem from how people/manufacturers decide to measure them. Diameter, ring gear diameter, pressure plate bolt diameter, or clutch surface diameter.

And again as far as I can tell, when talking a two piece rear main SBC, A 168 tooth flywheel is always the big clutch, and 153 is always the small one. If you see 12" or 11", the 12" is 168. If you see 11" or 10.4", 11" is 168.

I believe the 4500s were all the "big" clutch. In 1995 it looks like all manual trans half tons got an ~11" *clutch disk*, which means the flywheel diameter will be significantly larger diameter if using any measurement besides clutch engagement surface.
 
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dyeager535 said:
As far as I can tell, the small block two piece rear mains flywheels are all either 153 or 168 tooth. The confusion seems to stem from how people/manufacturers decide to measure them. Diameter, ring gear diameter, pressure plate bolt diameter, or clutch surface diameter.

And again as far as I can tell, when talking a two piece rear main SBC, A 168 tooth flywheel is always the big clutch, and 153 is always the small one. If you see 12" or 11", the 12" is 168. If you see 11" or 10.4", 11" is 168.

I believe the 4500s were all the "big" clutch. In 1995 it looks like all manual trans half tons got an ~11" *clutch disk*, which means the flywheel diameter will be significantly larger diameter if using any measurement besides clutch engagement surface.
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Is the bolt pattern on the 168 tooth flywheel universal for either of the 11" or 12" clutchs?
 
I think generally the 11" and 12" is the same thing. Not always, the listings are all over the map. If I am putting a clutch in a full sized truck, it's getting the largest of the two offered sizes regardless, and it will be the 168 tooth ring gear.

So many years have passed maybe there are one offs that slipped into the mix or something...

The pressure plates for the '74, '85 and '89 K5's, plus '95 K2500 are all the same. That means the flywheel bolt pattern for the plate is the same. All are the "big" clutch. The clutch disk between an '85 or '89 K5 and '95 K2500 are different.

A '74 K5 and a 1967 Camaro share the same flywheel IF the Camaro was a 350. The 327 at least that year, only got the 153 tooth flywheel. However for some reason, the pressure plate and clutch disk between the two is a different listing. It may be the difference between cars and trucks. If the flywheel is the same, the bolt pattern is too.

Whoever has mated a 4500 to a two piece rear main small block. Thats the combo someone needs to recommend.

Im not clear how the throw out bearing design works, perhaps that changed the design of things a bit. Doesn't seem likely in regards to the clutch disk, since the pressure plate and flywheels are the same from '89 to '95. Maybe it's based on the GVWR.
 
Unless I'm am missing something how about ordering a flywheel for a 1970 C-20 with a big block 396.
Internally balanced, 12" clutch and will bolt to a 327.
 
Capt Ron said:
Unless I'm am missing something how about ordering a flywheel for a 1970 C-20 with a big block 396.
Internally balanced, 12" clutch and will bolt to a 327.
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I thought the big blocks were externally balanced? I have a flywheel from a 1984 Chevy 454 with a 12" clutch that I wanted to use but read somewhere it was externally balanced. Is there a break somewhere in the timeline maybe?
 
CUCV2 said:
I thought the big blocks were externally balanced? I have a flywheel from a 1984 Chevy 454 with a 12" clutch that I wanted to use but read somewhere it was externally balanced. Is there a break somewhere in the timeline maybe?
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Only 454s are externally balanced. 396/402/427 are all internally balanced.
 
When I swapped in a SM465 on my '72 K5 ,(formerly a TH350),I used the flywheel,clutch setup and bell housing,and tranny from a totaled '72 K5..The bell housing it had was the "old" cast iron style that had motor mount castings made onto it (but were not used on that year vehicles)...
GM used them from like 1955 -72,then they began using aluminum ones ,and some accepted both 11" and 12" clutches,some had a removeable bottom cover,others were cast as one piece..

I bought a 12" clutch (3 finger borg & beck junk style,unfortunately) that bolted right up to the flywheel where the original 11" clutch went..far as I know the 11" & 12" pressure plate bolt patterns are the same,at least on that vintage truck..on many manual transmission trucks the starter bolted to the cast iron bell housing with 3 bolts,not to the engine block..

There are different bell housings though,some cars and trucks had one that would only fit an 11" pressure plate,while the bigger bell housing that accepts the 12" clutch will work for both..often the smaller one had the 153 tooth flywheel with a 10.5 or 11" clutch and the starter used the "straight across" bolt pattern on the block..
 
Thanks for the info. I found a GM flywheel today that seems like it will work. It's a 168 tooth, internally balanced, pre 1984, 2.5" center bore flywheel with the right bolt pattern. We put an 11" and 12" clutch on the same flywheel and, like you said, they had the same bolt pattern. Hopefully all the bases are covered because the flywheel is getting resurfaced and clutch parts are on the way. Thanks for all the help. I will post up with progress pics as it goes together to verify the fit and function.
 
Your welcome--I have no clue about using a later style hydraulic throwout bearing on an older bellhousing arrangement,but others here who've done NV4500 swaps will likely know what part numbers to use..
I found out the stock throwout bearings come in 3 different lengths,depending on which pressure plate was used...
The longest bearing was used with the "flat finger" smaller clutches (10.5" & 11") and another "medium length" one was used on most of the 3 finger borg & beck pressure plates,and the shortest one of the three was used on the "raised diaphagm" pressure plates..

I had to pull a SM465 transmission out twice to change throwout bearings after I found out the hard way I had put the shortest one in ,and I had a 3 finger pressure plate...if I adjusted the clutch to have the proper free play,it wouldn't fully release,and grind gears when I shifted from neutral and while driving...if I adjusted all the free play out,then it shifted fine,but now the bearing was always contacting the pressure plate..

This also was a problem on my '75 2WD K5..I put a Saginaw 4 speed in it from a '74 Vega and all was well until I found out the throwout bearing in it from the 3 speed clutch setup it originally had used one of the other length throwout bearings,and now the clutch slipped unless I adjusted alll the free play out..drove it a week that way.

So out came the transmission again,in the middle of January,on a slush covered driveway,lying on a blue tarp a whole day....the kicker was I had all 3 types of bearings in my garage left over from the '72 K5 swap ,but never thought to check which length it needed..:doah:

That is when I decided to start buying clutch kits with all three pieces included,rather than piece meal things together..:surepal:..
 
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