Is 345 FWHP Enough ?

[KiwiGT]

I've got a 1966 A code auto GT fastback. The car has all the usual suspension mods (shelby drop, 620 coils, konis front & rear, 1" sway bar, poly bushes front and rear etc). My 225hp 289 is original, unmodified. So now that I've got it handling, it is time for some horsepower. I kind of like the idea of the Ford Racing M-6007-XE3M crate engine (302CID, 345 fwhp). The main reason it is attractive is that I don't live in the US, so don't have easy access to other crate engine builders such as CHP, DSS, Keith Craft etc, but I can source the FRPP engine right here.

My car is 100% street driven, C4 will remain in the car for now, as will the factory 3.0:1, 8'' diff. I'm looking for something that will give me a grin on my face in acceleration terms up to 70mph. I am trying to achieve a 'balanced' car - good handling, and sufficient power without getting into the downstream drivetrain/traction problems that monster torque/hp can bring. So, I'm looking for opinions - is 345hp enough ??

 

[SadbutTrue]

a 345 hp car will definitely make for a fun ride. Plus, if you're looking for longevity with your parts (as it appears you are, keeping the 8" and C4), then its probably good to go with that and nothing more powerful. Make no mistake, however, that a 345 hp engine is more than enough to break that 8" inch rear (and same goes, for a lesser extent, with the C4... though my C4 has been fine behind my 351w for years and I don't treat it too well).

I think you'll behappy with that engine. I would strongly consider a 9" posi down the road though.

 

[KiwiGT]

a 345 hp car will definitely make for a fun ride. Plus, if you're looking for longevity with your parts (as it appears you are, keeping the 8" and C4), then its probably good to go with that and nothing more powerful. Make no mistake, however, that a 345 hp engine is more than enough to break that 8" inch rear (and same goes, for a lesser extent, with the C4... though my C4 has been fine behind my 351w for years and I don't treat it too well).

I think you'll behappy with that engine. I would strongly consider a 9" posi down the road though.

Thanks. Will one of the new Currie 8" centers do the job, or is there no substitute for a 9" ?

 

[SadbutTrue]

I'm not saying an 8 inch will definitely break under that engine. It depends more on a) how much torque the engine makes, b) whether you use sticky tires or not, and c) the type of transmission.

Sticky tires and a lot of torque = death for most rearends, especially the 8". The fact that you are using an auto is good, since it doesn't shock-load the rearend and transmit quite as much power as a manual does.

I'm also not sure which, but some years 8" housings were stronger than others. Might want to check that out. I'm sure the Currie peices will work, if you want to spend the money. But even a stock 28 spline 9 inch is stronger than a Currie 8", and it can be had cheap if you spend some time looking.

 

[bigcat]

yeah, thats plenty of power for the street. i had a 351C 2V and it had more than enough power (240hp supposedly but lots of torque). it was faster than MOST cars on the street. it only had 3.00 gears as well, but it was a 9". if you are not beating on it, it should last a while, but remember it is almost 40 years old....

 

[dodgestang]

Just one small caveat...unless you plan on running all the exact components they run on the short block when tested, you won't see that FWHP number. And even if you do, you might only get close. Its not that cut and dry when buying a crate motor.

With that said, plenty of power for what you have defined as the sole use for the car.

 

[Edbert]

Your 8 should last just fine unless you get great traction and use high RPM launches. Normal or even spirited driving you'll be fine, just don't drag race it with that 8.

 

[mfp4073]

I have one of those. With a 650 holley dp, weiand single plane xcellorator, longtube headers/2.5inch exhaust/flowmaster delta 40s and got a 290hp/290tq to the rear wheels on a dyno(mustang dyno). That was with power steering and a solid fan. Pretty close to the 345 number by the time you kick it back to the flywheel. That would be about a 15% loss through the drivetrain.

 

[mfp4073]

oh yeah, and with my 245/60 tires I can chirp 2-3rd shift and sometimes get 3rd to 4th to chirp if I get it just right. At 30 in second I can stomp the pedal and roast the rear off the car. It took some tuning, but yeah the motor has a lot of kick and is rather comfortable as a driver.

 

[KiwiGT]

I have one of those. With a 650 holley dp, weiand single plane xcellorator, longtube headers/2.5inch exhaust/flowmaster delta 40s and got a 290hp/290tq to the rear wheels on a dyno(mustang dyno). That was with power steering and a solid fan. Pretty close to the 345 number by the time you kick it back to the flywheel. That would be about a 15% loss through the drivetrain.

Great, thanks...anything you'd change in your setup ?

Is it enough - you don't find yourself hankering for more horsepower ?

What sort of longtube headers ?

 

[rbohm]

will 345 fwhp be enough? not for a 9 second car, but for a good dd yes.

 

[Venomous1]

I have the same engine with a Perfomer RPM intake, 670 Street Avenger, and Tri-Ys going through a T-5 to a 9" locker. Although I haven't had it dynoed or anything yet because I am still fine tuning, it has plenty of power.
As far as is it enough power, I think that depends on the person. I think I will be pulling that engine and tranny out and going with a stroker and a TKO, but I am kind of a speed freak...hehe. However, if you are looking for a driver that puts a smile on your face when you punch the gas, look no further, this engine is your ticket. Hope that helps.

 

[SoCalCruising]

68-up 8" rearends had extra ribs on the center section for a bit more strength. The Aluminate seems, by specs and other comments of this board, to be stronger, yet. The cheapest thing to do would be to swap center sections from a '68-up donor with the same gears. Otherwise, swap the gears in yours to the donor. If y ou move up to a stroker, you really must move up to the 9" in order to have some margin for safety.

 

[mfp4073]

problem is that I cant use the power that I have. Traction is such an issue...then making the car stronger to deal with the traction. But yeah, for me its enough. Its a lot more tricky a motor than I was going to put in the car. I honestly cant think of anything that I would have done different at this point.

 

[KiwiGT]

I have one of those. With a 650 holley dp, weiand single plane xcellorator, longtube headers/2.5inch exhaust/flowmaster delta 40s and got a 290hp/290tq to the rear wheels on a dyno(mustang dyno). That was with power steering and a solid fan. Pretty close to the 345 number by the time you kick it back to the flywheel. That would be about a 15% loss through the drivetrain.

mfp4073 - does the cam on those engines have a bit of a lope at idle, can you tell its got a bit of cam in it ?

 

[jeb134]

I also have one in my car with a 650 Demon and Edelbrock Performer RPM intake and it's a great daily driver. You can tell the cam has a bit of a lope at idle, in fact when it's cold, it really has one! But once it's warmed up and ready, it pulls really nicely from 1500 and up.

 

[KiwiGT]

I also have one in my car with a 650 Demon and Edelbrock Performer RPM intake and it's a great daily driver. You can tell the cam has a bit of a lope at idle, in fact when it's cold, it really has one! But once it's warmed up and ready, it pulls really nicely from 1500 and up.

Thanks Jeb. I was looking for that V8 lopey cam sound, so thats good to hear.

 

[mfp4073]

I can "tune" the "lope" up or down...more or less noticable with the idle mixture and idle rpm. I often tune it to rock and roll at idle a little more then it should just for fun sake! Its cool to sit at a light with the car rocking around. But I can tune most of it out too if need be. But there is still a noticable difference than a stock cam. I know people that say they can tell that its a roller motor by the sound of the cam too....but I dont know how.

 

[cougar694u]

I dyno'd at 340 to the rear wheels with 4.56 gears (that high gear fools dyno's and will actually dyno lower than with lower gears). I'm running a C4 with no problems, so I think your c4 will be okay. My brother, on the other hand, dyno'd over 600. Third gear died in his car, but luckily, Performance Automatic has a lifetime warranty.

And, to your question, is 345 FWHP enough? No, it's never enough. I told myself that a 13 second car was enough. Now I'm itchin to pull that 11.99, or faster, out of the hat...

Either way, you'll be satisfied with it going from your 289 to this motor, you'll love it, and there's always room to grow.

**EDIT**
Wow, when did I become a senior member?