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73-87 Chevy _ GMC Trucks => Performance => Topic started by: 81k10427td on March 05, 2013, 03:35:35 pm
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hi im new here and i know this was probly discussed before but cant find any info. how fast can a 427 tall deck spin with 6.535 rods on regular pistons. im building one for my pulling truck and so far i have a cam (dont remember the specs) prolly putting bigger valves in the heads and thats all i can think of off the top of my head. thanks for any help
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A lot of things will limit your RPMs. I had problems breaking valvetrain parts on my sled puller, never bottom end stuff.
Since you are buying all new stuff why not drop in 6.8" rods? When I build my 427TD it will have a 6.8" rod on a 4.25" stroke. Anytime you can put in a longer rod it will translate into more torque, and a more free running engine.
I know guys running stroker engines with factory GM blocks to 8,600RPMs in their pull trucks.
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OK i would be happy with 6000 rpm when I'm pulling so i might need to change pushrods to just to be safe (not sheer how much the stock ones are good for) don't really have to money for a stroker crank but will build one down the road (not for a long time lol) I'm pulling in work stock gas and with 4.10 gears and need as much tq and rpm as i can get lol
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I built a 505 Tall Deck origanally for my Stepside but I decided to re purpose it for my Nova Drag Car. I started with a 427 TD out of a big truck, Bored it to 4.350 (+.100) after some math I found an off the shelf Piston for it to use with a set of 6.800 Rods, They happen to be the same Piston I used in my Stroker 489. And I used a 4.250 stroke crankshaft. It will have a F2 Procharger on it and will be ran on Alchol
The reason I decided to build a tall deck was because with a Boosted engine I wanted to have a Big Bore, and Long Stroke crankshaft. By using a 6.800 rod I was able to get my Rod To Stroke ratio of 1.6. The thearory is that you get More cylinder filling due to the piston hanging at TDC for longer and you have a better Rod to Stroke Ratio for less cylider side loading, I guesse I'll just have to wait to see for myself at the dragstrip.
One other note, The Tall Deck is .400 Taller that the Standard Deck. (Standard deck = 9.800/ Tall Deck = 10.200) By Using a 6.535 rod your Piston will be .265 below the deck of a Tall Deck.
If you want I can post Part numbers of this engine, It has yet to be fired but it is built and I have the procharger, I got wrapped up trying to finish my Twin Turbo 489 so I put this on the back burner for a bit.
Hope this Info Helps