f_inscreenname

Just broke down a 427 tall deck. I've been told that it's a stroked 482ci. It does have a 4" stroke crank and LS 6 454 pistons but I have no clue what these rods are. They have a number on one side (I cant find anything on it) and the other side looks like its been ground on. It's like that on all 8 rods to.
The number is 621-3404. Any help?

FIXX

iTrader: (2)

mark they look like stock rods but they are side polished and most likelt shot peened and a good rod bolt installed..you sure its a 4'' stroke? the 427 T D came with 8:1 forged pistons..back in the day we would swap the ctlinder heads with rectangle port heads.add a asolid roller cam and lap a 671 blower on top..quick way to make 650 hp..

Mbam

I am pretty sure that is an old Kiekhaefer rod. They were used on the 482's back in the day. But like Fixx says are you sure it is a 4" stoke? The 482 was 4.25

f_inscreenname

This is what I've I.D'ed in this motor so far.

Block
340220 .... 427T ...... 68-85 ... 4-bolt 1972-76 427 tall truck
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Crank 3963521 454 - 4 in stroke, 5140, raw forged –part # 3963524
(The crank has a 3521M on it.) This forged 5140 steel 4.00" stroke crankshaft is the highest quality GM offers for big-block V8s. It is nitride treated to increase its hardness and fatigue strength. The main bearing journals are cross-drilled to provide a constant supply of oil to the rod bearings. For use with Mark IV design engines only. Technical Notes: This crankshaft is externally balanced. It must be used with a counterweighted torsional damper and flywheel (or flexplate) for correct engine balance. Main journal diameter is 2.75"; rod journal diameter is 2.20". Crankshaft ID is #3521.". GM parts direct sells them for $700.60. List is $962.36
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Heads 3964291
RECTANGULAR PORT - Valve size 2.19 intake, 1.88 exhaust
1969-70 396/402 375 L-78, Intake Port 325cc 427 425, 435 L-71/L-72
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Crane Cams Part Number:138091
Mechanical roller tappet / Grind Number:TR-252/400-2-10
Basic Operating RPM Range:3,500-7,000 / Intake Duration at 050 inch Lift:252 / Exhaust Duration at 050 inch Lift:262 / Duration at 050 inch Lift:252 int./262 exh.
Advertised Duration:290 int./300 exh.
Factory Rocker Arm Ratio - Intake Valve Lift :0.680 in. / Exhaust Valve Lift :0.708 in.
Valve Lift with Factory Rocker Arm Ratio:0.680 int./0.708 exh. / Lobe Separation (degrees):110
Intake Valve Lash:0.022 in. / Exhaust Valve Lash:0.022 in.
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3906629 oil pump
OEM GM Oil Pump Assembly with P/U For Chevrolet/Corvette Big Block Engines. The part number in the casting is 3906629 GM3
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Main Bearing
5203 / .010
Rod Bearing
(6) 5177 / .010 - (2) 5177 / .020
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Pistons 3999295 454 - LS6 - 1971 - 9:1
Pistons Part number=6262976
Engine=454
Compression Ratio=9:1
Size=Std.
Dome Type=Closed
Pin Type= floating
Should originally be from a 1971 LS-6
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Holley 850 D/P
list # 4781-2
model # 4150, 850 CFM
Dbl pump
80 jets in both ends and a 6.5 power valve in both ends
renew kit part # 37-485

f_inscreenname

Also notice the cut on the crank rod journals. Never saw 2 different sizes before (the .020 over size is on 7 and 8's journal).

sprink58

Not sure...I will defer to Mark. Looks like a casting mark that a specialty casting shop would use that matches a customers PO #. nice looking piece of hardware BTW.

mike tkach

iTrader: (3)

my guess is it probibally spun a bearing and instead of regrinding all the rod journals they just did the bad one,back in the old days a lot of things were done as a quick fix.

mike tkach

iTrader: (3)

i have never seen that rod before but it looks heavy.

Mbam

Yes, they are very heavy! I had 2 sets of them in the 482's that came with my Cig when I bought it back in 1978.

f_inscreenname

Very heavy. They make the Scat *26385716 - 6.385 in. Connecting Rods - Floating Pins -I Beam Forged 4340 steel I have in my 496 look like toys.



Marc, you have any specs on them? Like length and such?
Also were your 482's full roller motors? Before I got it I did a little research on the 482. I expected aluminum roller rockers but this one also has a roller cam and lifters, 7/16 pushrods and guides, rotators taken out of the rectangle heads with big valve springs.