408 hp?

[66ls427]

How much hp and tq are you guys making with the 408's?

Currently I'm running a 351w, 30 over Edelbrock rpm heads (2.02, 1.6 vavles) and intake, holley 750 dp, hydrolic flat tappet (not sure on the cam specs). Around 9.5:1. On the dyno it made 380 lbs. tq at 2700, and 310 hp at 5000.

If i stroke it to 408, the only thing I am planning on changing is the stroker kit and retrofitting a hydrolic roller cam.

Will the rest of my combination flow enough for the 408?

[blykins]

I'd say your heads will choke it down a little...Edelbrock heads are good, but even my Victor Jr's don't flow as much as the real high end AFR's and TF's...You'll probably be at 450 hp I'd estimate.

[Curt C.]

I assume you are talking rear wheel numbers? My 351W (standard bore & stroke) made 377 RWHP and 355 RWTQ which equates to 450 flywheel hp assuming a 15% driveline loss. Utilizing ARF 185 heads (2.02 vlave) and a hydraulic flat tappet cam with 236/246 duration and 520/538 lift. Suffice it to say, there is a lot more power available in your motor. Cam specs would help us better evaluate your situation. Of course, there is always a compromise to be made with respect to streetability vs. power. How fast do you want to go? Or, do you just want a 408? This stuff is so much fun!

[66ls427]

Curt C. What rpms did u make your peak numbers at? and what compression? Which do you think would be cheaper for me? Upgrade my 351 or stroke it? I also want a big lope too.

[Curt C.]

Car peaks at about 5900 for HP and 4800 for torque. I should also mention that the hp stays pretty flat all the way out to 6500. Around 9.8:1 compression. Again, how much power do you want? To achieve a power level simillar to mine, no question - upgrade. You have decent heads already. Tell us more about the cam, carb, intake and exhaust. Cams, and intakes are cheap and hold lots of power. Oh, yes, I have a fairly nasty lope.

[66ls427]

Not sure about the cam specs, but it has absolutely no lope. Carb is holley 750 dp mech. Intake is Edelbrock rpm. Header primaries are 1 5/8. Also running a 1 inch spacer. I would like an engine just like yours.

[Curt C.]

I run a holley 750 race DP on a Victor Jr. The RPM manifold is a good intake, but will not make as much power as the Victor between 4000 and 7500 - maybe 15 to 20 less a peak. Do you know if the cam is a roller? I think it is pretty clear that you have a very mild cam in that pup (ie. no lope). My cam is a ford mortorsports M-6250-A351. It makes over 300 RWTQ at 3000 RPM. See my gallery for a pic of the dyno run.

Comp Cams tech is very good. Also, a lot of guys on this site as well as www.corral.net are very good at picking cams. Spend some time and ask a lot of questions. Just make sure you are honest with yourself about how high you want to spin the motor. If you are not careful, you can end up with something not very streetable. My engine is the 385 HP ford crate motor with a set of AFR 185 heads. While the block is a Sportsman model, the crank and rods are not forged pieces. Hence, I shift at around 6200 on the road course. I have shifted as high as 6800 on the drag strip. Also, make sure to order the right type of cam for which your block is currently set up for: roller, non-roller hydraulic, solid etc.

I believe there is an easy 50 hp in a simple cam swap. Throw on a set of underdrive pullies ($100), put a good K&N filter on if you dont have one already and head back to the dyno. Take the time to tune the carb and play with the timing while on the dyno. Also, investigate the actual sidepipe muffler itself. Sidepipes are notorious for sucking out huge HP figures. I have heard that even some of the better pipes out there can swallow 100 HP on a big block If you have a restrictive bullet muffler in the sidepipe, there could be lots of power on the table there too.

I recently had a new set of sidepipes made that are totally tunable with excellent guts including collectors costing $250 a pop and the muffler insert costing $300 a pop. I tested these on the dyno and the difference between the low setting (quiet) versus the medium setting was 50 hp - yikes. I will post the whole sidepipe story complete with dyno figures and pics soon in the Shop Talk forum.

[66ls427]

Thanks for all the info. As soon as I save some money, I'll start ordering parts.

[grego37]

Just picked up my stroker (351w) 408 from the dyno.
498 HP (at flywheel)
495 TQ
9.8:1 compression, on 91 octane pump gas
TFS R-series heads out of the box, power up to 6000 RPM
32 degrees total timing.

cant wait to drop it in the car!

[CobraEd]

You must have a VERY mild cam! Stock 351 cam?????

[grego37]

the cam I went with is
crower 15359 but I used 1.7 ration rockers, bringing lift to just under .600
242/250 @50
112 lobe seperation
regular solid lifter cam

I was willing to sacrafice a little power for more streetability etc...
thanks