If you'll indulge me, I really would like to know A: What's so

unique

about the 4 port '75 motor, and B: why it's sought after. Consider it
an opportunity to educate me so I can know my motor - at least another

one of them!

'74 & '75 engines had intake ports that closed 10 degrees later than
'76-'85 4-port engines. Street ported engines typically have intake
ports that close 20-30 degrees later than stock '76-'85 ports. Other
than longer intake port timing, there is absolutely no reason to want
these older engines except for core parts to build other 13B engines. If
you are porting, you can make the same size ports regardless, while the
older side housings are not nitrided and have a much shorter service
life.<<<

Marc Wiese

 
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