unknown_host

iTrader: (1)

What kind of times/horsepower are you getting? I am thinking about stroking my 350HO to a 383HO this summer with a big flat tappet cam, then switching to AFR 195's and a solid roller cam the following summer.

Anyways, are vortec heads too small for a 383 would you say?

Ray87Z

Well, I haven't done it myself, but the March 02 issue of HotRod has a bolt on dyno article about the GM 383 crate engine which has Vortec heads. It's sold as a truck motor, so it has a weak cam, low compression etc stock.

With the GM medium rise dual plane intake, headers, and a 625 Road Demon carb it made 338hp/444ft-lbs stock.

With 1.6:1 rockers it went to 355hp/452ft-lbs.

With a RPM Airgap intake it shot to 370hp/466ft-lbs, then a larger 750 Demon carb was swapped on to make 379hp/474ft-lbs.

Next they had the heads machined/clearanced for more lift, put on new valve springs and ran a CompCams XE282 hydraulic roller cam. (230/236 @.050, lift of .510/.520 {.544/.555 with the 1.6 rockers}). They also ran thinner head gaskets to get the compression up from 9.0 to 9.6ish:1. It then made 455hp/493ft-lbs. Idles at 950 rpm with 12 inches of vacuum according to them making it still streetable.

Then they added Royal Purple synthetic oil to get 463hp/502ft-lbs. And that was it for this article, not too bad for stock (other than valve springs/clearancing) Vortec heads.

Hope that is a little of what you wanted to know.

unknown_host

iTrader: (1)

Your the man dude!!!! :hail:

87Formula391S/C

iTrader: (1)

read this post by mike crews he has one of the badest 383's with vortec heads..Sammy


383 Vortec TPI Dyno Results (and questions) ( 1 2 3 4 ... Last page )

unknown_host

iTrader: (1)

I have looked over it, but I am carbed so a lot of his TPI related stuff doesnt apply to me. Thanks for the suggestion tho. Anyone else?

82 Bracket Car

Heads will be fine. I have a set on a 406. Don't know what the hp/tq numbers are, but I have run a best of 10.47 @126.9 with a 1.42 60ft time in 3150 lb car. These heads work. They still have 1.94/1.50 valves and have been ported and polished and have screw in studs. The motor has a solid lift cam and flat top pistons. The carb is a demon 750.

r90camarors

I'll be able to tell ya her in a couple of weeks. I've got the Pro Topline vortec heads on my 383 with a comp cams 305-8 and a performer dual plane. Engine is going in this weekend, though breakin and chip tuning will be a few weeks. Of course, the heads are port and polished with an angle job done on the valves.......

black84-6spdz28

i also have the protopline vortecs......i have a 357 with a comp cams 274h and this motor has *****!...these heads rock

r90camarors

sweet, sounds like a nice engine black84. I wasn't sure if anyone on this board was using them. The guy building my engine uses the protopline vortecs on his 305 race cars at the local track-and has taken first for the last two years. The heads flow more straight outta the box as compared to gm's, and if you buy the heads complete, I believe they can handle a .500 lift from the factory. I think they are really close pricewise as well.