« previous next »
Pages: [1]   Go Down

Author Topic: 421 or 434  (Read 3414 times)

Offline grapro

  • Jr. Member
  • **
  • Posts: 71
    • View Profile
  • Your Track: edmonton
  • Your Vehicle: 184" FED
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.
Logged

Offline jeff/21

  • Full Member
  • ***
  • Posts: 186
    • View Profile
  • Your Best Time: 8.24
  • Your Track: any with-in a 6hr radius
  • Your Vehicle: fed
Re: 421 or 434
« Reply #1 on: September 30, 2018, 03:39:59 PM »
Any difference other than size?
Logged

Offline Paul New

  • Hero Member
  • *****
  • Posts: 743
    • View Profile
  • Your Best Time: 6.47 @ 214 MPH SBC
  • Your Engine: 387" SBC
  • Your Track: Woodburn Dragstrip
  • Your Vehicle: 2005 FED
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
Logged

Offline wideopen231

  • Hero Member
  • *****
  • Posts: 1911
    • View Profile
  • Your Best Time: 1/8 3.70@ 198 1/4 5.78@245
  • Your Engine: Hemi 526 ci alcohol
  • Your Track: Piedmont
  • Your Vehicle: 225 CMC FED
  • General Location: NORTH CAROLINA
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.
Logged
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot
Pages: [1]   Go Up
« previous next »