Trying to get a little more done to my SD4 project today. Dropped off my 437 SD4 head at the engine builders to get some flow numbers to help with turbo decisions. I was told the head, most likely, came from a racing boat. The intake valve was a 2.125", WOW, I didn't think they would go that big for a 4 banger. Also the ports have been ported and polished to the extreme of having to epoxy the intake runners because they got into the push rod area. Was told it wouldn't last long in a street engine but could be fixed at a reasonable price. So a couple more weeks and I'll post my flow number results.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

Get 'er fixed properly and let us know the results! We'll be waiting!

Well I got good news and bad. The bad, I forgot my flow sheet at my GF house. The good is it flows 230 @.700 on the exhaust and 306 @ .700 lift on the intake. I also took my 801 head to discuss how much better it might be. We decided the 437 would be better since it has already been ported and polished, plus it will be boosted.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

[This message has been edited by Lilchief (edited 03-20-2011).]

After some more research, the intake valve is a big block pontiac 455, 2.110. It's written at the bottom of the page. The exhaust is only a 1.60 , but that may be a good thing since turbos like a bigger intake which sometimes uses a larger intake duration on the cam. In this case they may be the same between int/exh.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42