Engine in my trans am is a 400 with cylinder heads stamped 99. I looked them up and they are indeed 1971 heads that were rated at 265hp from the factory. Trying to find out which car these came on from the factory so I can figure out if those ratings were with a 2 barrel carb or 4 barrel. The heads are 98cc.

http://www.wallaceracing.com/head1.htm

 

That doesn't say what car came with the heads, just HP rating and stuff. I want to know what model pontiac vehicles had these heads.

The 1971 RPO L65, 265 HP 400 cubic inch 2bbl with the 99 heads were put into a variety of cars given the popularity of the 400 engine and the economy of the 2 barrel carb. These engines were put into Firebirds (F-bodies), Catalina/Grandville (B-bodies), and Lemans/T-37 (A-bodies) although I can't imagine they were put into the GTOs, Trans Ams or Grand Prixs. These engines could be mated to either a 3-speed manual transmission or TH400. The matching block casting number should be 481988.

Edited January 2, 20188 yr by Frosty

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