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Author Topic:   double humps or 300 horse heads
posted June 03, 2003 04:26 PM
i am running a 355 ci chevy small block with a bowtie intake and a holley 4412 built by jet performance with headers running 112 octain on a 3\8 mile dirt track wich heads should i run a set of 300 horse heads with 1.94 valves or a set of 327 double humps with 2.02 valves i dont know the part # but any suggestions

thanks dave

posted June 03, 2003 04:31 PM
If you have to stick with stock castings, of the 2 I would say the double humps. If you can go aftermarket i would reccomend those over anything stock.

posted June 03, 2003 04:35 PM
they must be stock casting because i have a set of brodix alluminum heads with 2.05 valves that i would love to run but i cant

posted June 03, 2003 08:52 PM
Hump head #461, 462, or the 492 are good OEM heads but all the information I've heard is the vortec will out flow these hump heads (if you can run vortec heads.)

posted June 03, 2003 09:00 PM
If you can run the vortec i would defintely run them, they will run circles around the others. They are pretty near a sportsman head in flow and chamber design. Most rules i have seen that outlaw aftermarket heads also include vortecs for some reason but maybe you are lucky.

posted June 04, 2003 10:50 AM
Are all votec heads the same?. And what years would be the best to find ?.

posted June 04, 2003 01:06 PM
The true vortec are mid 95 and later on pickups etc. stay away from the 89-95 tbi head that some call vortec they are nowhere near the same.

You can buy brand new vortec heads from chevrolet for about 480$ a pair complete. the only thing is they will deefinetly need different springs and possibly some valve guide machining depending on your cam. At one time i knew a place you could get a set of reworked vortecs with ***** in studs, z28 springs and stainless valves for around 650$ dont know if its still out there though.

Let me know if you need more info. I have been through the vortec swap before so i know what interchanges and what doesnt.

posted June 04, 2003 07:50 PM
scoggin dickey perf sells new vortecs for 400.00

jr motorsports had reworked ones i think for 650-700


posted June 05, 2003 11:13 AM
just checked scoggin dickeys website
-standard vortecs good to .450 lift-$244/ea complete
-upgraded with z28 springs good to .525-$320ea complete. (in my opinion too much lift for z springs)
-double humps BARE castings 310ea
plus shipping which could be 40-50$

If it were me i would get the stock vortec and upgrade the springs myself..and got o ***** in studs. I wouldnt run z28 over .480 lift.

posted June 11, 2003 11:06 PM
Do you guys run the vortecs with guide plates or the "self aligning" rocker arms?

posted June 22, 2003 03:16 PM
The new pro topline vortech cylinder heads for 305 and 350 are better but I don't know if your race track will go for that.
Thanks, Ron

posted June 23, 2003 09:37 AM
The only vortec swaps i have done are on the street so i have used the self aligning rockers. On the race track i would definately use the guide plates if rules allow. If you do you will need to clearance the pushrond holes in the head. And if you use center bolt valve covers you will have to use narrow body rockers. If you use the center to perimeter bolt cover adapters i beleive you can use the more common rocker.

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