Thread: 409 ?
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Old 07-27-2010, 08:26 PM   #25
vectorit
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Join Date: Jun 2007
Location: Southern California
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Re: 409 ?

Quote:
Originally Posted by Davetopay View Post
1.The "W" designation was NOT a reference to the heads. It was part of the alphabetical series of design studies the development team at GM used to differentiate between the candidates in the big block V8 program.

2. I wouldn't go looking for a ready to run motor, especially if you are looking for speed. Get a clean 409, and swap in a 2 piece seal 454 crank to get a 481 stroker. The mains on the 454 crank will need to be turned down .250" and you will need to turn the snout down to 1.250 and use a 400 SB balancer. You will have to clearance the block a tiny bit for the rod bolts.

Use a 6.135" 454 connecting rod. Eagle makes one that is nice with a bushed small end.

If you are using a big cam with huge spring pressures, swap up to a good small block set of bearings and add the oil feed holes to the number 5 bearing and make sure the cam shaft has a fully grooved rear journal to insure proper oiling to the lifters.

409 heads will take 2.250/1.725 valves with the seats cut to fit as a drop in replacement.

Regular big block rockers will work just fine. Just call your favorite cam grinder to set up specs for your goals.

For improved oiling us e a Melling M99HVS pump with a hardened shaft. It will fit inside a 409 pan. You can adapt a mordern spin on filter mount to make things easier/cleaner to deal with, but the old WIX cartridge style holds more oil.

If I had the time/money/space I'd be all over having a 409 in a 2wd swb.
Interesting write up there!

I've always liked these motors, since they are very different.
My Dad always reminisces about the days he ran around Pasadena in his 409 61 4 speed Impala back in the 60's.
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