Just spotted these (http://store.summitracing.com/partdetail.asp?part=SUM%2D152123&N=115+%2D42064+%2D45166+309823) in the newest Summit Catalog. They also have a vortec version. (http://store.summitracing.com/partdetail.asp?part=SUM%2D151124&N=115+%2D42064+%2D45166+309822) Price looked fair, I just thought I'd pass it along.

I kinda wonder why they did that backwards? They put big valves in a smaller runner head(165cc) then put small valves in the larger runner head(175cc) I wonder what the philosophy is behind that one? :confused:

Who are they made by??

Generic, cast-iron, Pro- or W/P's??

pdq67

well with a 165 intake runner, what upgrade are you getting here? Looks as these are just a stock replacement not exactly built for performance?

These are not bad for the price. If they have accessory holes I would look hard at these. I guess the springs are about SS but I like the duals.

I think they are more like the 461s and not the 461X but they should still flow very well for the street.

Digging up an old post, but does anyone have any new info on these heads?

Or better yet, run a set?

Thanks!!

Digging up an old post, but does anyone have any new info on these heads?

Or better yet, run a set?

Thanks!!I'm running the non vortec ones. They are dart castings. I believe when I bought them they were $580 for the set. They have fast burn chambers. Good mild performance head imo if you don't want to go the vortec route.

I'm running the non vortec ones. They are dart castings. I believe when I bought them they were $580 for the set. They have fast burn chambers. Good mild performance head imo if you don't want to go the vortec route.

Thanks for the reply dude.

Are you running them on your blown motor?

Thanks for the reply dude.

Are you running them on your blown motor?Yes:)

I kinda wonder why they did that backwards? They put big valves in a smaller runner head(165cc) then put small valves in the larger runner head(175cc) I wonder what the philosophy is behind that one? :confused:


I'm running the non vortec ones. They are dart castings. I believe when I bought them they were $580 for the set. They have fast burn chambers. Good mild performance head imo if you don't want to go the vortec route.

If they are Dart heads it is odd that the version Summit sells them having 2.02/1.6" valves and the one's Dart list on their website have 1.94/1.5" valves.

Maybe the Summit version is speciality made for them?

If they are Dart heads it is odd that the version Summit sells them having 2.02/1.6" valves and the one's Dart list on their website have 1.94/1.5" valves.

Maybe the Summit version is speciality made for them?I'm really not sure,I know the castings are dart going by the #'s. I know dart also makes a stock replacment vortec head which might be what the vortec summit heads are.

I really have no idea why they got 2.02 valves or if they were machined/assembled by some other place.

Maybe they come from these guys, who knows...

http://www.chevyhiperformance.com/tech/engines_drivetrain/cams_heads_valvetrain/0606ch_cylinder_head_performance_test/aerohead_racing.html

They are hands down way better than any stock gm casting quality wise.

Based on a visual inspection, they appear to be made by World. I was in the Georgia Summit store yesterday and purposefully compared the heads on display to determine who makes them. A few visual cues that are similar to world heads and different from dart: valve stem bosses, exhaust manifold mounting flange and water passageway openings.

John

Based on a visual inspection, they appear to be made by World. I was in the Georgia Summit store yesterday and purposefully compared the heads on display to determine who makes them. A few visual cues that are similar to world heads and different from dart: valve stem bosses, exhaust manifold mounting flange and water passageway openings.

JohnStrait from dart...

The DRT007 casting number indicates our Iron Eagle S/S head. The "Thunder" name is likely a private label name used by a distributor.

All of the S/S heads come with a 165cc intake runner, not 180cc. They are made in the U.S., not New Zealand. To get more specifics, we would need the eight digit part number, which should be stamped on one end of the head.

Greg Wold

Dart Machinery, Ltd.

Okay, I got alittle bonus at work today and I have decided to buy a pair of these Summit heads.

Here's the thing, which one should type should I buy? One set is the old style GEN I heads and the other are Vortecs. I haven't bought any other parts like intake, etc that would sway me to one or the other so I can pretty much do as I want. The only thing the GEN I heads have over the Vortecs is 2.02/1.6" valves VS. 1.94/1.5". But the Vortecs are listed as having 170cc intake runners and the GEN I are 165cc's.

They would be used on my rebuilt, balanced 355 short block and either head will give me alittle over 9:1 CR with my Speedpro pistons. The cam will either be a Voodoo 60101 or 60102 (haven't decided yet). The intake will a dual-plane with a Q-Jet pattern so I can coutinue to run my old trustly Q-Jets and keep reasonable mileage. The complete motor is being tossed into my K5 4x4 (Built 700R-4, 4.11 gears, 33" tires, 1 5/8's coated full-length headers, dual 3" exhaust, etc) that is currently being used as a daily-driver.


So, what do you guys think? Vortec or GEN I Summit Heads?

Pro's and con's?

Thanks!!

I kinda wonder why they did that backwards? They put big valves in a smaller runner head(165cc) then put small valves in the larger runner head(175cc) I wonder what the philosophy is behind that one? :confused:

I think that would be to get velocity up and improve cylinder filling. I'm just guessing tho.

http://www.cardomain.com/ride/3886517/1978-buick-regal/page-4
dart casting part #10021111

yeah I had some of the vortec version on a 350, ran very well and would handle up to a .520 lift cam, although I ran a .480 lift. Got my full size truck movin enough to run a 15.45 @88 mph with a 3.08 rear gear and a TH400

I built a 355 roller for a guy last summer and we tried a set of the summit 'vortec' based heads. They flowed about 10cfm BETTER than a GM vortec on the intake side, and about the same on the exhaust side. the intake port is not raised like a true vortec, more of a stock port with a half-circle cut out of the roof. A little gasket match had it fixed!
they came with umbrella seals and a decent single spring for a flat tappet motor (IIRC 100# seat, upper 200s @ .500) (I cut the guides for a good PC seal and cut pockets for larger hyd. roller springs) Plenty of room for improvement and I bet a little touch up and good valve job would wake em up- however, we left these ports alone. The engine was a very mild application with 9.5:1, .510 roller with .050's in the upper 220s, performer intake and edelbrock 750 carb, calibrated for economy. It did not make the power I expected but I do not think it was the heads holding it back (upper 300s hp/tq) theres better heads out there for a race car, but for the average joe street/strip application, i think they are a very good head for the money.