Hey guys, I am looking to get a few opinions on my new head, cam, headers, and intake combo. I currently am running an 87' 5.7L L98. It has all the basic bolt on's (except headers, but that will come in with this combo while it is all apart) and TPI mods. I am looking at the SDPC vortec base, L31 vortec heads, and the LT4 hotcam. I have a buddy who is very knowledgeable kinda pointing out that the LT4 hotcam is a "short runner" style cam and may not be a good matchup with this installation. I hear about people running the LT4 HC with stock L98's and it doing well on here. Is this accurate? Does anyone have this combo or results?? I am looking to buy this setup once, and would like to avoid expensive mistakes. I will more than likely be getting the SLP runners and porting the intake to match along with 1.75 headers at the same time. Opinions, thoughts??

 

Sounds like a real miss mash to me.
It may all fall together, make huge power and they'll all have to re-write all the how to books ever written. But if it was a good combo either price wise or power wise.
some one would be selling it.
Al thou Vortec's are beauti heads, why go
with them when you'll have to buy expensive adapter bases and new springs and other valve train to work with the hyd roller cam.
Get a great 23deg street head like Edelbrock performer rpms or ported L98's or Darts or
pro action's. they all will bolt up to your tpi base and make lots of power for less $.
Even a set of ported camelbacks (186,492 etc) will kick butt. I would not commit my self to a LT4 hot cam either. Get the "Hot Cam" that matches the combo you're building.
Check out the T.P.I.S. and SLP sites and get recomendations from Cam Companies (Crane Cams, Comp Cams etc) You can do this online or phone. Just tell them about the other parts you want to use and they will match up the right cam and kit for you.
for ya. Nothing against the vortec's (I have them myself) I just can't see useing them on a TPI when there are other heads which are just as good and bolt right up and come with most of the valvetrain you'll need. Personally I'd go for the RPM's With a little home porting and a Crane Power Max Street Roller KIT that matches the SLP runners.
Just my .02

 

Thanks! Anyone else?

 

someone just emailed me and suggested to look at some cams from Lingenfelters. i think they make some special for tpi and others for other intakes if you want it to match. i was thinking of using a lt1 cam but i may look into those lingenfelter cams more.

i heard diff stuff about the heads like edlebrock heads don't flow that good but they work really good when you put them on a engine.


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1986 Iroc 305 small block chevy getting modded now for speed

 

Keep in mind, the Vortec's don't have the EGR passages, so you'll need to plumb them from your exhaust. I've kind of heard that this can be done with a kit from Edelbrock and one or two GM parts, for about $100, at least for the Vortec TBI intake. You'd have to contact SD about their TPI plate to see if that same setup will work, or maybe they know of another way to retain EGR.

If you do decide to go Vortec, Edelbrock has new E-Tec heads out that outflow GM's Vortec heads, and come with screw-in rocker arm studs and better valve springs. I'd check them out before you make a choice.

As far as heads go, the AFR heads are supposed to be some of the best street legal heads around, and you can even order them already CNC ported. You'll have to ask them which version is best for you, they have two different runner volumes available.

Then maybe ask them for cam recommendations, they'll be able to tell you what duration and lift will work best with their heads and your purposes.

As a general rule of thumb, build your car around the cylinder heads. Pick an appropriate pair of high performance heads, find a matching intake, and a cam who's lift and duration matches the flow characteristics of the head.

Just some manufacturers for you to check out that make good street legal heads: AFR, Edelbrock, Trick Flow, GM (Fastburn, L98, Vortec), World Products (good low price heads), etc.

Remember flow is not everything, an engine can only provide so much vacuum so the idea is to match components so they complement your engine size, desired RPM range, and each other.

Hope this helps, any questions, just ask

Jason