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Author Topic: 421 or 434  (Read 3383 times)

Offline grapro

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421 or 434
« on: September 30, 2018, 03:28:40 PM »
Looking at purchasing a new sbc shortblock from Shafiroff and debating on which one. Have a set of Promaxx 225 heads and my Hilborn stack injection. Have a set of 4.30's in the pumpkin and not sure which way to go. 421 or 434.
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Offline jeff/21

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Re: 421 or 434
« Reply #1 on: September 30, 2018, 03:39:59 PM »
Any difference other than size?
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Offline Paul New

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Re: 421 or 434
« Reply #2 on: September 30, 2018, 04:02:50 PM »
I would ask them which would build more power with the heads you have.  If it’s NA remember the old saying no replacement for displacement
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Offline wideopen231

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Re: 421 or 434
« Reply #3 on: September 30, 2018, 06:57:49 PM »
Only reason I can see for buying smaller engine given choice would be if it had smaller bore and could be bored out more later. Other wise go as big as you can afford.
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