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A short cost analysis of converting to Vortec (L31) heads.
I'm currently running 882 heads on my 355 SBC and became interested in using the Vortec heads.
I did some checking around and located a price of $209.01 from Jim Pace Pontiac and saw advertised (but haven't called on) a price of $399.50/pr from Scoggin-Dickey. List is $269 each. The following is a short, quick and dirty, analysis of the cost associated with converting to these heads.
There are several issues one needs to attend to for this conversion.
The Vortec head uses the new self-aligning rockers, consequently your old style rockers will not work without some machine work. If you want to use your older style roller rockers or other non-self-aligning rockers you must machine and tap the heads for screw in studs and use guide plates. Other than that, replacement with self-aligning rockers, either Chevy or aftermarket, is the only alterative.
Next are the valve covers. The Vortec head uses the center bolt style covers. You need to include the cost of replacing your existing covers or buying GM's $108.00+ (list $182) adapter. If you use roller rockers you must use perimeter bolt (old style) covers and the adapter plate.
The last issue is the intake manifold. You can either drill and tap the head to use your old one or replace it with the Vortec manifold. I was told by one sales person that because of the raised intake runners in these heads, using the old manifold blocks off part of the port on the head. This creates turbulence and upsets the flow to the valve, defeating, at least some of the advantage these heads have. GM wants $225+ for the Chevy branded manifold and Jegs has the Edelbrock branded version (7116 IIRC) for $175.
I don't have all the prices for everything but lets take a look at some numbers.
Least expensive option
This option uses your old manifold.
Heads ..................... 399.50 - 418.02
Rockers ................... 50.00 Approx
valve covers .............. 50.00 Approx
mounting studs for vc ..... 30.00 Approx
TOTAL ..................... 529.50 - 548.02
More expensive, uses Edelbrock manifold
Heads ..................... 399.50 - 418.02
Rockers ................... 50.00 Approx
valve covers .............. 50.00 Approx
mounting studs ............ 30.00 Approx
Manifold .................. 175.00 Jegs (Chevy's is $225)
TOTAL ..................... 704.50 - 723.02
More expensive yet, manifold and old style valve covers
Heads ..................... 399.50 - 418.02
Rockers ................... 50.00 Approx
Adapter for valve covers .. 108.00 Best price I found, list is $182
Manifold .................. 175.00
TOTAL ..................... 732.50 - 751.02
More expensive yet, manifold, old style valve covers and self-aligning roller rockers
Heads ..................... 399.50 - 418.02
Self-aligning Rockers ..... 300.00 Jegs (Crane 10751-16)
Adapter for valve covers .. 108.00 Required for roller rockers
Manifold .................. 175.00
TOTAL ..................... 982.50 - 1001.02
How about re-using your old style roller rockers
Heads ..................... 399.50
Adapter for valve covers .. 108.00 Required for rockers
Manifold .................. 175.00 required for best performance.
Machine work & screw-in
studs ..................... 85.00-100.00 ????
Guide plates .............. 25.00 Approx
TOTAL ..................... 792.50 - 807.50
I didn't include gasket, since they are required for any head change, or hardened pushrods, since any guide plate engine needs them (be sure to add in their cost if you need to buy them).
In conclusion, since World's Sportsman II heads can be bought for approximately $800, the cost to use Vortec heads in an engine with roller rockers doesn't make much sense. Add to this the less durable, light weight castings and the comparison looks even worst.
Even going for the least expensive option is questionable. Loper's has an ad in the June 99 Super Chevy offering the SR Torquers for $550 a pair fully assembled (this is with screw in studs but not guide plates (which may not be necessary)).
I don't know how well the Vortec heads compare with these World heads, flow wise or power wise. They may compare very well with the Torquers, but I would guess the Sportsmans are more powerful and both are more durable. Plus you get a choice of combustion chamber sizes with both World offerings. 64cc is a little small for use with flat top pistons.
As I said above, I don't have prices for every thing and guessed at some. However, I think these ball park figures give a pretty good idea of the total cost involved to convert to Vortec heads. And remember, these are with the best prices I found. Vortecs are going locally here for $225 (one dealer) to $269 (6 other dealers) each.
Comments?
Pat
[This message has been edited by Pat Kelley (edited 04-15-99).]
[This message has been edited by Pat Kelley (edited 04-16-99).]
I'm currently running 882 heads on my 355 SBC and became interested in using the Vortec heads.
I did some checking around and located a price of $209.01 from Jim Pace Pontiac and saw advertised (but haven't called on) a price of $399.50/pr from Scoggin-Dickey. List is $269 each. The following is a short, quick and dirty, analysis of the cost associated with converting to these heads.
There are several issues one needs to attend to for this conversion.
The Vortec head uses the new self-aligning rockers, consequently your old style rockers will not work without some machine work. If you want to use your older style roller rockers or other non-self-aligning rockers you must machine and tap the heads for screw in studs and use guide plates. Other than that, replacement with self-aligning rockers, either Chevy or aftermarket, is the only alterative.
Next are the valve covers. The Vortec head uses the center bolt style covers. You need to include the cost of replacing your existing covers or buying GM's $108.00+ (list $182) adapter. If you use roller rockers you must use perimeter bolt (old style) covers and the adapter plate.
The last issue is the intake manifold. You can either drill and tap the head to use your old one or replace it with the Vortec manifold. I was told by one sales person that because of the raised intake runners in these heads, using the old manifold blocks off part of the port on the head. This creates turbulence and upsets the flow to the valve, defeating, at least some of the advantage these heads have. GM wants $225+ for the Chevy branded manifold and Jegs has the Edelbrock branded version (7116 IIRC) for $175.
I don't have all the prices for everything but lets take a look at some numbers.
Least expensive option
This option uses your old manifold.
Heads ..................... 399.50 - 418.02
Rockers ................... 50.00 Approx
valve covers .............. 50.00 Approx
mounting studs for vc ..... 30.00 Approx
TOTAL ..................... 529.50 - 548.02
More expensive, uses Edelbrock manifold
Heads ..................... 399.50 - 418.02
Rockers ................... 50.00 Approx
valve covers .............. 50.00 Approx
mounting studs ............ 30.00 Approx
Manifold .................. 175.00 Jegs (Chevy's is $225)
TOTAL ..................... 704.50 - 723.02
More expensive yet, manifold and old style valve covers
Heads ..................... 399.50 - 418.02
Rockers ................... 50.00 Approx
Adapter for valve covers .. 108.00 Best price I found, list is $182
Manifold .................. 175.00
TOTAL ..................... 732.50 - 751.02
More expensive yet, manifold, old style valve covers and self-aligning roller rockers
Heads ..................... 399.50 - 418.02
Self-aligning Rockers ..... 300.00 Jegs (Crane 10751-16)
Adapter for valve covers .. 108.00 Required for roller rockers
Manifold .................. 175.00
TOTAL ..................... 982.50 - 1001.02
How about re-using your old style roller rockers
Heads ..................... 399.50
Adapter for valve covers .. 108.00 Required for rockers
Manifold .................. 175.00 required for best performance.
Machine work & screw-in
studs ..................... 85.00-100.00 ????
Guide plates .............. 25.00 Approx
TOTAL ..................... 792.50 - 807.50
I didn't include gasket, since they are required for any head change, or hardened pushrods, since any guide plate engine needs them (be sure to add in their cost if you need to buy them).
In conclusion, since World's Sportsman II heads can be bought for approximately $800, the cost to use Vortec heads in an engine with roller rockers doesn't make much sense. Add to this the less durable, light weight castings and the comparison looks even worst.
Even going for the least expensive option is questionable. Loper's has an ad in the June 99 Super Chevy offering the SR Torquers for $550 a pair fully assembled (this is with screw in studs but not guide plates (which may not be necessary)).
I don't know how well the Vortec heads compare with these World heads, flow wise or power wise. They may compare very well with the Torquers, but I would guess the Sportsmans are more powerful and both are more durable. Plus you get a choice of combustion chamber sizes with both World offerings. 64cc is a little small for use with flat top pistons.
As I said above, I don't have prices for every thing and guessed at some. However, I think these ball park figures give a pretty good idea of the total cost involved to convert to Vortec heads. And remember, these are with the best prices I found. Vortecs are going locally here for $225 (one dealer) to $269 (6 other dealers) each.
Comments?
Pat
[This message has been edited by Pat Kelley (edited 04-15-99).]
[This message has been edited by Pat Kelley (edited 04-16-99).]
