More HP or lower gears?

[Joe383]

"However, good heads (with 170-180 cc intake runners) and a mild roller cam can give your 350 the best of both worlds."

I would rather have heads that were a little too large over a cam that was a little to large though. 400HP takes a lot of cam or a lot of head. You would need a cam with about 240* duration at 0.050 with a 170cc head and would be spinning the motor around 6,500K The larger heads would allow same power at lower RPM with less duration. Good example of this is GM ZZ5 crate motor compared to say the Edelbrock performer RPM. About same rated HP and torque but I bet the ZZ5 is a was smoother motor with a lot more low end torque.

 

[TheBeast80]

That's a good idea, I might put in a limited slip for the rear

 

[MadOgre]

That's a good idea, I might put in a limited slip for the rear

I would go Detroit True Trac

 

[TheBeast80]

I was just looking at one on eBay for 540? Any suggestions on brand of gears?

 

[HotRodPC]

DAMN !!! Nice truck though. Don't worry, that stuff wipes right off and adds a little shine. I'm sure I wasn't the first.


Yep, if you're attached to the 700r4, and doing a gear swap, get your money's worth and go at least 5.13's maybe 5.38's since you're running such a tall tire. That'll take alot of stress off the 700r4 and get you moving much easier.

If you're running a 14b Full Floater in the rear, keep in mind, 4.56 and higher numerically, you'll have to buy a carrier too, since cut off is 4.10/4.56. Now my might find some aftermarket thick gears that will allow use of the 4.10 and down carrier.

 

[TheBeast80]

It's a 14 bolt semi float not the full floater. Do I need to work about a carrier with that axle?

 

[HotRodPC]

It's a 14 bolt semi float not the full floater. Do I need to work about a carrier with that axle?

I won't swear to it, maybe someone else can confirm, but I've not heard of this axle having a cut off. I think the same carrier will work with all gear ratios.

 

[68post]

HotRod you are correct, ( I double checked at "Tom's Differentials" ).

 

[TheBeast80]

Great, is that the same for the corp 10 bolt?

 

[68post]

Great, is that the same for the corp 10 bolt?

No, not the same !

 

[TheBeast80]

Alright, so I will need to get a new carrier for the 10 bolt? I'm just trying to figure out whether I need to order for these 4.88 gears

 

[68post]

No, not the same !

Sorry, let me clarify. For the 8.5"/8.6" corporate 10 bolt.
If your original carrier is for a 2.41 or 2.56 gear ratio - then you'll need a new carrier for a different ratio than those two gears.

If your original carrier is for a gear ratio of 2.73 or numerically higher ratio, ( 3.08, 3.23, 3.42, 3.73, 4.10, etc..), you are ok.

2 series or 3 series carriers.

( I have a set of new 5.57 gears - if you really want to gear it down )

 

[jmbcary44]

and post up pics on whatever you do!

 

[Driver4r]

"However, good heads (with 170-180 cc intake runners) and a mild roller cam can give your 350 the best of both worlds."

I would rather have heads that were a little too large over a cam that was a little to large though. 400HP takes a lot of cam or a lot of head. You would need a cam with about 240* duration at 0.050 with a 170cc head and would be spinning the motor around 6,500K The larger heads would allow same power at lower RPM with less duration. Good example of this is GM ZZ5 crate motor compared to say the Edelbrock performer RPM. About same rated HP and torque but I bet the ZZ5 is a was smoother motor with a lot more low end torque.

dont agree.... The bigger the heads on a smaller engine, the more you have to spin it to make power..... you can only shove so much air in a set space.
Bigger runners make an engine a dog if its not built to handle the air you are trying to shove in it.

But when i say big runner, im talking 200+ on a 350. You dont need a 210CC runner on a stock engine with an RV cam.
Now if i build an engine with alot of overlap 320ADV Dur.. theres alot that gets lost thrue the exhaust, so i need to move that much more air.

 

[TheBeast80]

I have 4.10 gears now so it sounds like I can just buy the gears, I'll take pics of everything bf and after install