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Marv D · 07-06-2014, 03:25 PM

Just curious to what 'stroker' he's building??? You can fit a 3.875 stroke in a 4" bore block with a LOT of work,, for 395 inches @ +.030. The specility pieces needed for the 'odd ball' strokers are ,,, well,, Of those I've built are seldom worth the added expense of staying mainstream.

The 7-4, (2-3) swap gives you the same firing order as the LS motors. Supposed to give you a smoother idle and help reduce the intake reversion and pulsing of the 5-7 firing order. We did a motor and the cam grinder I was working with said there was an identical build he had just finished with the 7-4 swap cam. In the end,, the cam grinder said the 7-4 swap motor made 2HP more than my standard F.O. (that was at the 660HP solid roller range) My dyno report was from a SF901 and supposedly the other motor was also on a superflow dyno. That's all strictly 'as I was told', And because of that I never bothered with a 7-4 swap in any of my own stuff.

If your looking for every last HP for some heads up racing the swap is maybe worth while,, but if the cam grinder is charging extra for the core to build the swap cam,, Is 2 PEAK HP really worth it to you???

07-06-2014, 03:25 PM	#11
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: Engine Build ? Just curious to what 'stroker' he's building??? You can fit a 3.875 stroke in a 4" bore block with a LOT of work,, for 395 inches @ +.030. The specility pieces needed for the 'odd ball' strokers are ,,, well,, Of those I've built are seldom worth the added expense of staying mainstream. The 7-4, (2-3) swap gives you the same firing order as the LS motors. Supposed to give you a smoother idle and help reduce the intake reversion and pulsing of the 5-7 firing order. We did a motor and the cam grinder I was working with said there was an identical build he had just finished with the 7-4 swap cam. In the end,, the cam grinder said the 7-4 swap motor made 2HP more than my standard F.O. (that was at the 660HP solid roller range) My dyno report was from a SF901 and supposedly the other motor was also on a superflow dyno. That's all strictly 'as I was told', And because of that I never bothered with a 7-4 swap in any of my own stuff. If your looking for every last HP for some heads up racing the swap is maybe worth while,, but if the cam grinder is charging extra for the core to build the swap cam,, Is 2 PEAK HP really worth it to you??? __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.