Subject: Re: Building a boost friendly 400 by PeteK on 2013/11/10 14:21:10
Quote:
bogus wrote: under normal conditions - meaning cars with airflow - that would work.
The C4 does not have very good under hood air flow.
I would get a highrise hood to allow the heat out.
And BC is right, blower speed is the key to power... same applies to turbo's...
My concern with the 400 block is the limits on heads and intakes... the deck height is different. Also, the OEM 400 had some seriously thin cylinder walls. It was just pushing the SBC to a limit. I know that the aftermarket has some bad ass blocks, but this just doesn't sound like a practical fix.
Either go smaller, or go nuts and do a small big block.
Personally, a 383 will do all of this... without needing custom bits... AFR heads that fit... intake options...
All external dimensions are the same for a 400 block. Any "traditional" small block head or intake, and headers will fit.
Ford guys have fits when the jump from the 302 block platform to the 351 block platform.
In regards to cylinder wall thickness, my experiences are opposite. Post 1977 small blocks (regardless of size) have thin cylinder walls. The 400's that I have been involved with have sonic checked thicker than the typical 1 pc rear main seal block that is the norm in todays builds.
I never did understand the heat concern with a 400 block, and aluminum cylinder heads. Old wives tale that I have never seen happen.
