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#1
04-07-2021, 01:03 PM
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670 heads?
Hey guys,
I am trying to acquire things for my build as I go,engine will be hopefully a 389 but may go with a 400 and I plan on stroking it. There is a guy with some 670 heads for a decent price was wondering how good they were or if I should pass them up? Seems like they are good flowing high compression heads according to what I can find. Eventually down the road I'm gonna buy some either edelbrock or kre heads. |
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#2
04-07-2021, 01:36 PM
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The 670 heads flow better at .250" to .300" then any other D port head and will make for a Good compression on a stock Bore 389, but there's a potential issue in that if your running 389 type valve releaf pistions with the 670 heads you can only safely run .450" valve lift due to the valve inclination difference between 389 heads and 400 heads.
Also most 670 heads have chambers of 74 CCs, so on a .030" 400 motor you will need to keep a close eye on your compression in regards to any milling the heads if needed or decking the block.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
| The Following User Says Thank You to steve25 For This Useful Post: | ||
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#3
04-07-2021, 02:13 PM
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Ok but with Ross pistons from butler is the valve clearance issue still present?
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#4
04-07-2021, 03:23 PM
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What are the pistons for a 389 or a 400?
If there made for a 400 then your set! In terms of clearance.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#5
04-07-2021, 04:43 PM
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Just read in a post yesterday that if you use a shallow chamber high compression head with dished pistons to lower the compression, at higher lifts they will have less valve shrouding than some of the heads with deeper chambers. And the dish in the piston allows for more cam lift.If you are planning to stroke it, that would raise the CR with stock 670 heads pretty high. I had a set of 670 heads that had been milled a couple times and they measured at about 69 cc chamber.
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#6
04-08-2021, 04:11 AM
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670 or other iron heads can be made to perform very well - just toss a whole bunch of money at them and they will make good power. You will need pistons with a large dish and other corresponding parts that will later become problematic when you step up to aluminum heads. If you want the best bang for the buck and not have expensive parts sitting up on the shelf after a later swap to aluminum heads, just lay out the money now for aluminum heads and buy everything once in a nicely balanced engine package.
__________________
Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon in progress. |
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#7
04-08-2021, 06:40 AM
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To the OP, please reply back with info as to if it will be stroked now during the rebuild , or down the road?
Your post is confusing because it's sounds like you have a 389 to run now, and then will build a stroked 400 based on another block, is this the case?
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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