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#1
08-15-2004, 06:58 PM
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I am planning to do a performance build on a 75 455 block. Most of what I have read seems to indicate that the 455 were pretty much equal (except for SD 455) throughout production but I was recently told that a 70 455 bock is substantially stronger in the main webbing area than a 75 455 block. Is this true? If so, what year did they reduce the strength? I have 2 other blocks, a 72 and a 73 that I could use if they are superior to the 75 block.
Thanks, Joel |
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#2
08-15-2004, 06:58 PM
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I am planning to do a performance build on a 75 455 block. Most of what I have read seems to indicate that the 455 were pretty much equal (except for SD 455) throughout production but I was recently told that a 70 455 bock is substantially stronger in the main webbing area than a 75 455 block. Is this true? If so, what year did they reduce the strength? I have 2 other blocks, a 72 and a 73 that I could use if they are superior to the 75 block.
Thanks, Joel |
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#3
08-15-2004, 07:05 PM
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I have been told that the "72" cast number 485428 is a very good block to use.
__________________
You know it's going to be a good day when you wake up breathing! |
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#4
08-15-2004, 07:12 PM
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It depends. SOme blocks were just cast thicker. I'd put my '75 2-bolt main block against any '70 block in terms of thickness in the main webbing area.
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Just a blind squirrel looking for a nut. |
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#5
08-15-2004, 07:37 PM
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I had a 76 2-bolt block that had a thicker web than my current 74 4-bolt casting! I also have a 71 4-bolt that I would only trust as a street/strip block as the web is thin and the core shift is way off, the lifter bores are drilled off-set making them thick towards the rear off the block and extremely thin towards the front... D. Miles
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Going TurboCharged! |
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#6
08-16-2004, 05:01 AM
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I was looking at my 71 and 73 455 blocks over the weekend (71 is drilled and tapped for 4 bolt). The surfaces where the main caps mount are about the same but the 71 steps down thinner above the mounting surface. The 73 is pretty much straight.
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Todd Sedlmeier Who ever thought pinewood derby cars would lead to this! October 2004 HPP Shootout participate http://www.highperformancepontiac.co...out/index.html 86 Grand Prix 535 High Port 8.93 @ 153 65 GTO 433 High Port 12.04 @ 113 |
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#7
08-16-2004, 06:03 AM
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<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Brian Baker:
It depends. SOme blocks were just cast thicker. I'd put my '75 2-bolt main block against any '70 block in terms of thickness in the main webbing area. <HR></BLOCKQUOTE> 
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#8
08-16-2004, 06:32 AM
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I am running a 1975 455 block in a 67 Firebird.
The car has run 11.62 @ 118 MPH 3650 LBS and been together for over 11 years. |
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#9
08-17-2004, 06:27 PM
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I am having a hard time following exactly what too look for and since I don't have 20 bare blocks laying around to look at and compare I was wondering if someone has any photos that would illustrate exactly what to look for. Is it the part of the main web that extends out to the pan rail or the area between the main journal bore and the cylinder walls (or both) that is most important to look at?
Thanks, Joel |
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