bwkelley76

I did a search and couldn't find anything specific on this topic.

Conversion flex-plate...

Which is the proper flexplate used for a Late-Model (87-93) HO 5.0 in a '65 With C4?

Summit Racing says I need a 50 oz, 157 tooth flex plate with a 10.5" converter bolt pattern, and its only made by B&M for 120 bucks.

Hmm...

Is this the common combo used for the conversion? $120 a bit out of my price range right now.

I wonder if there are any factory production plates that will work, maybe I can score a good/used one??

I just spent 60 bucks on a new factory one not knowing the difference. I can swing 60, but can't afford $120 right now.

ewgoetz

The flex plate weight needs to match the motor not the trany. Also go to LMR I have found that there prices are a little cheaper than sumit is. ALso they have several listed there for you to choose from.
http://www.latemodelrestoration.com/...px?q=flexplate

uedlose

What trans bell size do you have is it a 157 or a 164. if your 164 dont it inside the bell of the c-4 you have then it sounds like you will need the 157 tooth bell and no there are no factory 157 50oz balance fly wheels out there that came on OEM stuff. you can switch the bell to a 164 and then you could use the trans and flywheel you have but you would still have to buy the bell. what spline converter does that thing take? if its a 65 trans it may be a 24 spline and if it is do yourself a favor and dont put big HP to it or you will twist or snap the input shaft. If I was you I would be looking around for another big spline tarns if it is the small one. then when you do that it will give you a chance to find one with a big bell. if it is the 26 spline input then you will be fine.

bwkelley76

I looked at the site and they are actually a little more expensive than summit options except for the SFI Approved one. ..only $107. Not bad! What I thought was strange is the SFI apporoved ones were cheaper than the regular ones in some cases. Non SFI approved was $134.00. Good info though, thanks.

I just ordered the TCI from Summit for $82 ..Seems fair enough on price. Better than $120 and I dont need the SFI for my application. Hays makes one for $74.00 but they are back-ordered through October.

Thanks for the help guys! I'll let you know how it all fits up.

bwkelley76

Good question and I think it's the 157 tooth. I am assuming the car currently has a 157 tooth 28oz flexplate instead of the 50 oz which is why it shakes.

The reason I say that is I tried using a starter from a 5.0 Mustang and the gear wouldn't even reach the ring gear, current flexplate is too small.

bwkelley76

How about the harmonic balancer?

This has the original v-groove pulleys on it. I wonder if they reused the original balancer on this thing.

Is there a way to tell by looking if the balancer is a 28 or 50 oz?

In case I do need to install a 50 oz balancer from a late-model, will it bolt up to my v-groove 4-bolt pulley, or am I going to have to buy a conversion balancer also?

ewgoetz

Should bolt up, the sn95 5.0's used a spacer between the balancer and the pulley I know that much.

bwkelley76

Ok, got it all figured out and fixed. It's a 1985 block (50 oz). I installed the custom TCI flexplate for conversion to 50 oz, the balancer was replaced by the previous owner and is actually already the right one for the 50 oz setup.

Turns out they had the wrong starter on this thing also (had one from a manual trans and it tore the crap out of the previous ring gear)

The best way to identify the 50 oz balancer.... The HO, 50 oz balancers have timing marks that go all the way up to 30 degrees, and the timing mark is set up for the passenger's side. (will not line up with an early timing cover when at TDC or using a light) Apparently they make a conversion balancer that has the marks in the right place for the older cover.

Hope this all helps with the next person that has to deal with this.