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Topic Review (Newest First)
01-09-2013 10:00 PM
RAYFIN I was just curious. I had a 68 camaro with a 3500 stall and 4.11 and I used to run a 3000 stall with 456's.
01-09-2013 12:24 PM
spinn It is a th350c 3000 stall built by dynamic converter and followed the manufactures cooler instructions. With the drivetrain it is locked up at 65mph. Backing up with a trailer there is no problem. Normal driving it isnt noticeable . It footbrakes to 2200rpm for a big launch. Temps are normal. Not really sure what tow condition you are worried about. Pulled a weight distribution hitch with 7500lbs trailer, and it was fine.

Most newer trucks have 2600+ stalls.

If you have some concern about stall converters contact dynamic converter. An automatic drivetrain that works together as a package is priceless. The trans can be pulled back in a afternoon , not a big project. Should install a shift kit while you are under there.
01-09-2013 12:06 AM
RAYFIN How does the 3000 stall work while towing? Just curious.
01-08-2013 11:35 PM
spinn In my 85 C10 , I swapped 601 58cc to vortec 906 heads. They were milled to 60cc. 305 with a perfomer intake on both pre/ and vortec. My comparison would be no loss in pulling power at low rpm. The low end was the same, the mid band was a big difference.

A 305 , Q jet, performer cam, 3.73, 3000 stall, 28" tire. The basic foundation for a driven muscle car/truck.

To be current it is now supercharged, but before it was as stated.

Can you tow a tractor. I have towed as much trailer wieght as my class 3 hitch allowed, hundreds of miles.
01-08-2013 11:20 PM
RAYFIN My brother put Vortec heads on a 400 SBC and he ran 13.0 sec at the drags with a huge camshaft. He went to a mild camshaft and ran about the same time. He said that was because these heads flow REALLY good. You should gain HP either way. He was a GM Mechanic for many years.
01-08-2013 11:18 PM
RAYFIN My brother put Vortec heads on a 400 SBC and he ran 13.0 sec at the drags with a huge camshaft. He went to a mild camshaft and ran about the same time. He said that was because these heads flow REALLY good. You should gain HP either way.
01-08-2013 07:00 PM
oldbogie
Quote:
Originally Posted by BuzzLOL View Post
.. That may be because they always increase the cam size as well...
No I talking head to head comparison on an otherwise idential engine or as much as it can be given the intake also needs to change in-so-far as bolt pattern is concerned so while it's the same intake model i.e. Edlebrock Performer RPM for example it still is not the same piece of equipment from one test head type to the other.

Bogie
01-08-2013 06:06 PM
BuzzLOL .. That may be because they always increase the cam size as well...
01-08-2013 06:01 PM
oldbogie
Quote:
Originally Posted by BuzzLOL View Post
.. The Vortec heads will help low end torque (1500-3500 RPMs) some if they offer a change from 76cc chambers to 64cc chambers... but I don't recall if the swirl port heads are 76cc or not... just remember the swirl ramps blocking the intake port flow...
There are 2 Swirl Port heads on the 350 engines the casting ending in 191 is 76 ish ccs the one ending in 193 is 64 ccs.

I have yet to do or to see a dyno run where the Vortec head picked up torque on the bottom end without also changing pistons from dish to flat top.

Bogie
01-08-2013 05:36 PM
cobalt327 5.7L SP = 64 cc
01-08-2013 05:01 PM
BuzzLOL .. The Vortec heads will help low end torque (1500-3500 RPMs) some if they offer a change from 76cc chambers to 64cc chambers... but I don't recall if the swirl port heads are 76cc or not... just remember the swirl ramps blocking the intake port flow...
01-08-2013 02:16 PM
oldbogie
Quote:
Originally Posted by lowhirod View Post
I,m after low in torque. I tow a 30 hp tractor with a half ton truck
In that case you're better off leaving it as original. Unless you increase the displacement anything you do to the heads or cam will reduce bottom end torque, push the torque peak an horsepower to higher numbers but also they will be at higher RPMs than what the current LO5 peaks at. This will drive you to stiffer final gearing to restore power at cruise back to where it was with the swirl port heads.

If you really need more bottom end the best way to attack the problem is with more displacement, and the best way to do that is with a 383 stroker kit. The other ways of getting there with the engine you have is with a stiffer rear axle ratio. This will give the engine more mechanical advantage in all gears and will cause it to operate closer to its torque and power peaks in normal use.

You have to keep in mind that new trucks since the mid 1980's are very much an exercise in systems integration design. The Swirl Port head is made to work with TBI and actually does very well with a carb. The Vortec was made to work with port injection and with that set up doesn't surender much if any bottom end torque. But when that head is mated to TBI or a carb a very noticable drop in bottom end torque is seen. The overall performance gain in this situation for the Vortec happens above 2500 RPM which is significant, but unless you rev the engine up you can't get that advantage with TBI or a carb and these heads.

Bogie
01-07-2013 10:04 PM
BuzzLOL .. Well, then, your current throttle body should be big enough/fine...
01-07-2013 06:54 PM
lowhirod I,m after low in torque. I tow a 30 hp tractor with a half ton truck
01-07-2013 04:29 PM
BuzzLOL .. A big advantage is Vortec heads can be scored used for about $100... grab the Vortec intake manifold with them...!
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