4l80e Flexplate 3 or 6 bolt?

[knarf]

Hello all,
I just replaced my engine with a fresh rebuild.... I have misplaced my flexplate so I ordered a new flexplate and now I am on my third flexplate and every flexplate I get only three bolts line up and the other three are off....
It's a 2000 Chevy express 3500 RV Feetwood Tioga with a 454 and a 4l80e.
These are the flexplates I have tried.
SCAT ‎FP-454-SFI
SCAT ‎FP-454L-SFI
PIONEER FRA111HD35
The last one was a GM part number given to me by the part counterusing the VIN.
So is this a three bolt or six bolt and if six bolt what's the part number. TIA

 

[Schurkey]

Three bolts line up, three don't? You've got a flexplate intended to mate with a larger-bolt-circle 3-bolt torque converter, or a smaller-bolt-circle 3-bolt torque converter. In other words, a semi-universal flexplate. MAYBE intended for a two-piece rear main seal small-block that could be mated with a TH400 (large) or TH350 (small) bolt-circle torque converter.

You need a flexplate with all six hole on the same bolt circle. A few TH400s got a six-bolt torque converter, and (I guess) all the 4L80E-series got the six-bolt converters.

When you get the flexplate, make sure it's got the proper balance weight on it. 454s with cast cranks use a different weight than 454s with forged cranks, and the older 2-piece rear main 454 (cast or forged crankshaft) flexplates may have yet a different balance weight.

 

[GoToGuy]

You replaced your OE engine, or you rebuilt your OE engine? The trans and converter are original or replaced.?
GM parts giant calls for 10101170. You could try their website with your VIN, you can't get more accurate than that.

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[knarf]

You replaced your OE engine, or you rebuilt your OE engine? The trans and converter are original or replaced.?
GM parts giant calls for 10101170. You could try their website with your VIN, you can't get more accurate than that.

You must be registered for see images attach

You replaced your OE engine, or you rebuilt your OE engine? The trans and converter are original or replaced.?
GM parts giant calls for 10101170. You could try their website with your VIN, you can't get more accurate than that.

You must be registered for see images attach

The motor is a complete rebuild from a donor RV... The transmission and converter are original... I called GM with the vin and they gave me this part number 101001170. I ordered this Pioneer FRA-111HD-35 from Rockauto which is a match to the GM part number and only three of the six bolt holes line up. This is flex plate number three.... This is getting expensive and frustrating as hell...

 

[NickTransmissions]

The motor is a complete rebuild from a donor RV... The transmission and converter are original... I called GM with the vin and they gave me this part number 101001170. I ordered this Pioneer FRA-111HD-35 from Rockauto which is a match to the GM part number and only three of the six bolt holes line up. This is flex plate number three.... This is getting expensive and frustrating as hell...

Go to a junkyard and locate one like the below which is what I believe you need. Pulled it (and the 4L80E+converter) from a 2000 Chevy 3500 van w/a 5.7 gen1 sbc.

 

[GoToGuy]

If you had your original engine then the normal , yr, make , model , engine size, trans model or by VIN , catalog application would work. Unfortunately when you did an exchange rebuild you removed one part of an equal equation.
Unless you verify by part number and visual confirmation, your " will fit, it's the same " . Might not be exactly the same.
As you found out, GM gave you the right part number, your engine has a different part number crank.
So like an engine swap, it's a mix and match. Fortunately with GM there is combo that's works, just a matter of " this one ? Nope, next ".

 

[JeremyNH]

Not for nothing but you don't need six bolts at the TC. Not ever. The bolt circle at the torque converter has pretty much exactly 3 times the distance to centerline that the bolt circle at the crank. Mechanical advantage being what it is means that the force at the TC bolt circle is 1/3 that of bolts at the crank circle. So even with half the bolts each bolt at the TC is only experience 83% of the shear force of the bolts at the crank. I would use the three bolt flex plate and drive around secure in the knowledge that my flex plate bolts will yield at the crank before they will at the TC. I'll also add that my 4L80e TC only has three holes drilled so I only use the three holes in the flex plate that line up.

 

[Schurkey]

The flexplate-to-crankshaft bolts are bigger diameter, go in tighter, and are most-likely a higher-grade bolt that the flexplate-to-converter bolts. They provide enormously more clamping force, and would have substantially greater shear strength.

 

[JeremyNH]

7/16 is a substitute for M10 using SAE bolts in flanges with metric holes in most substitution tables. The fastener higher torque of the crank bolts increases the strain taking them closer to yield not further from it. You may be right on the standard grade difference but just use ARP fasteners and neutralize that. What I say stands. Mechanical advantage is what it is and there's no way around the math. Three bolts at the TC circle carry less shear than six at the crank.

 

[knarf]

Go to a junkyard and locate one like the below which is what I believe you need. Pulled it (and the 4L80E+converter) from a 2000 Chevy 3500 van w/a 5.7 gen1 sbc.

Thank you, Nick, That is the the flexplate I need and your info helped me immensely. I found two online 1) Pioneer FRA-321 2) ATP-Flex Plate-Z-231. I ordered the 1st one and it arrives Monday so fingers crossed!