I love these comments. I have a stock block that runs mid 8's at over 160 in a 3400 pound street car. It has made as much as 1200 at the wheels but its not very tested, it only has 120 runs on it and about 1500 street miles. Then there is my nitrous car that's 372" (14:1 compression) that makes 645 on the motor (flywheel) and I hit it with another 275 of nitrous. But again its not very tried, it only has 300 passes on it and is 17 years old. I must have missed the memo on blocks breaking.
If you can find a set of W5's I highly recommend them. I have been running them for years and will support an easy 700hp. You want the later blue pipe plug version. I think mine flowed 340 cfm intake side and they weren't ported all the way. We need to leave some meat for strength incase of backfires. I also recommend calling IMM engines because he is very knowledgeable about the small Mopar stuff. I have used him for years and his porting is excellent (not to mention his machine work) and he is honest and not super expensive.
W5’s are good heads, I ran them for years. Guy I sold the car to just texted me this weekend, went
[email protected] at 3200+ pounds on super stock springs at Atco this past weekend.
That is an honest 700 horsepower. With that being said, I wouldnt say it is “easy” to do. That is a very well sorted out combo with excellent porting, agressive solid roller, gas ported 14 to 1 slugs, yada, yada. Quality machine work by Best machine.
Regards 340 cfm not even fully ported, benches are like dyno’s, very subjective. And the blue plug versions are indeed the latest numbers, but even they are poor castings that are prone to leak. Been there done that. Better than earlier versions, but still not good. Lots of variance from head to head as well.
Good design that suffered from poor casting quality unfortunately.
just my opinion, I ran them for a long time. And nobody any longer makes headers for them.
Would definately not be my first choice any longer for a build at that level, would use the Indy stuff, better choice at this point.