Tough decision...stroke a 351W, or build a 5.0 roller...

Your towers dont look cut in that pic. Is that your 408? I would much prefer building the 351 so even 500-600hp would be possible down the road. The bottom line is that the 351 is a stronger block, and Im sure a 408 will make at least as much, if not more power than a 347, and do so at lower RPMs. Oh, and lets not forget that I already have two 351s, and zero 5.0s

 

Oops, I got mixed up...Comet, you run a 347, not a 351, doh! I was hoping for pics of a 351 with the hookers on it.

 

Bossmav, thanks for the advice. I have decided to build a 408 stroker, using twisted wedge heads, victor jr intake(or maybe an rpm air gap...), a holley, and some flavor of hydraulic roller cam.

 

I will nit-pik a little...
450 rwhp is roughly 560 fwhp. Big difference.
Also, 347s suffer (my word) from rod angularty, rod ratio, and compression height problems... All of which are not too hard on power, however are very hard on durability.

I highly agree with the "best bolts you can buy, everywhere you can put 'em" philosophy posted recently though. Fasteners are the prime weak point in SBFs.
Dave

 

I know guys with 100,000+ miles on there 347 and they don't burn oil and they run great........

 

I don't really doubt you, yet I do doubt they have a full on 560 fwhp or even 450 fwhp (N/A of course).
I know that 347s are widespread and accepted, but IMO, there are too many strikes against durability compared to many other options.
Dave

 

I think that you are right about some of the old kits, the new kits take care of the durability issues.......have you ever had any experience with a 347??? Just like any performance motor, it's all in the quality of parts and quality of machine work.......

 

I have never owned a 347.
I know people with 347s, one is a good friend.
None have had issues... but none are high mileage.
My posts were my opinion that there are just better options.
I am not 347 bashing, just pointing out things to consider when choosing.
Dave

 

I was just going to reuse my stock bolts. Do you think that would be okay just until I can get some better ones? Seriously, I am not going to spend the money on a 600hp capable engine to reuse some factory hardware. ARP all the way for this engine.

 

I am not totally up on the physics, but studs are supposed to be stronger/better than bolts. Head studs can interfere with head removal in the Mav though. Something to consider.
Dave

 

The cool thing about ARP studs is that they have allen wrench holes in the tops so you can screw them in and out like bolts. I will likely run studs on both the heads and mains. I think you have to run special studs anyways to run a girdle.

 

So with all the above being said, If I had it to do over again I would probably have built a 351W stroker and said goodbye to the shock towers. I agree with using ARP hardware in a performance build as an absolute minimum. My arp head studs don't have a recess for an allen head on them but I wish they did.

 

Just a little FYI, here's the hooker 6208 thread, this should give you a better idea of how they fit.....

http://www.maverick.to/mmb/showthread.php?t=3049&highlight=6208

 

Canton will include ARP "bolts" with thier girdle not studs. Now this did bother me at first but after putting everything together I see way they when with bolts.

Don't reuse ANY old fastener that will be holding a moving part.
Bolts will lose 10 to 20% of thier clamping force after they have been installed and then removed. Now I'm not saying don't reuse your ARP bolts or studs but factory fasteners are how old?

Grade 8 bolts are fine for a factory stock engine but a 210,00 to 230,000 tensile strength fastener would be better for 6,000+ RPM's.
Don't mix grades of fasteners, if you use a grade 5 nut on a grade 8 bolt you now have a grade 5 bolt.

Always read the instructions... WHAT? I know that what you are thinking but some fasteners have a wet rating and some have a dry, if you torque a bolt to 100 foot pounds dry it would be 115 to 120 wet (with oil) so READ first.

As always just my .02

Bossmav

 

Good info, but I think you got that last part backwards...wet torque specs are always lower than dry in my experience Due to the added friction of a dry torque of course.