Truck 409 acquisition

northerndave

Well Known Member
#4
Ok thank you. That helps persuade me to look for new pistons. I want to go forged and i understand 11:1 will net close to 10:1 with cylinder notches. If i upgrade the pistons to forged, how strongly is it reccomend to go with the longer rods? And what type? I see show cars listing several options, h beam, i beam, bolt types and wrist pin styles?
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#8
I would go with the longer[6.385] rod even on a cruiser.The advantages over all would be worth it.Unless you're planning on a high rpm,high horsepower engine,there's no need for the H beam rod.Have the block checked for bore taper and out of round.Also,before you pull the pistons,measure the deck height for evenness as it's not uncommon for there to be some twist.Make sure that the block at all four corners is square.For 400,some head work with bigger valves,a small cam[something in the 224 in.,230ex.@.050 range],an Edelbrock small port single 4bbl.intake,a carb of around 750 cfm,and a small tube full length header and you've got an idle-5,500 power band daily driver reliable engine that isn't bad on gas once you get it tuned out.Your street tires will hate the torque [FUN] that this combo will make.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#13
What you want here is the piston made for the 4 inch stroke ,then use the 6.385 rod in conjunction with the stock stroke 409 crank.You'll have a lighter,more stable in the bore piston.Yes the hyd.roller is worth it over the long term.A flat tappet set up is cheaper until a lobe fails,then you get to buy those parts again,PLUS the extra work and parts required to completely go thru the engine in order to clean out the metal from the cam failure.Most of the cams that fall in the duration at .050 that you'd want for this builds intended use will have a lift in the area of .520-.550.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#15
Well,it sounds like the block is fairly square.I'd suggest mocking up a couple of new pistons and the rods and see where the deck comes to.An Icon piston in a squared block will usually come up at about .015-.018 down.The object of this exercise is to end up with a quench area of more than .034 but no more than .058.The closer to the minimum,the more detonation resistant the engine will be on todays [junk] fuels.
 

july2849

Well Known Member
#19
What value does a truck motor such as the one above have assuming its pretty complete needing an over haul?
Assuming it turns can you run one around using a compression tester to gage condition-say by taking out the other plugs?
Thanks
 
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