1966 ChevelleSS

[barnett468]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 66 L78 ragtop</div><div class="ubbcode-body">Hi Ronnie, you are not dreaming. Something did happen with the HP rating in 66. I have some GM docs on it and will be happy to share.</div></div><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Postsedan</div><div class="ubbcode-body">Please do share</div></div>Hello;

Here’s some info.

According to the article in the link below, the government was cracking down on high hp supercars in 65 so the mfg's agreed not to produce cars with more than 425hp for 1966 at least. All the 66 L72 427 engines were actually 450hp but they slapped 425 hp stickers on them and rated the hp at 5600 instead of 5800 rpm to get around the 425 hp limit.

Some people speculate that chev simply ran out of 450 hp stickers so they started using the 425 hp ones. This is not the case which is proven by the fact that chev did a recall on all 427 450 hp cars so they could install a 425 hp sticker to keep the gov happy.

The imposed 425 max hp limit is further supported by the fact that in 1966, both the 426 hemi and 427 dual quad center oiler ford were claimed by the mfg's to have exactly...425 hp.

The corvette 396 was advertised as 425 hp as well, however this is about as much as these engines really had anyway. The same engine was put in other models and rated at 375 hp.

http://www.corvette.net/cac/L72/A_St...450-HP_L72.pdf