Hello everyone,
This is my first post on here after owning a Third Gen for several months, and I've greatly appreciated the wealth of knowledge that's on this site.
That said, I looked and couldn't find info on a couple of items, so I figured I'd ask y'all.
I have a '91 Z28 with an LB9 and T5. I'm thinking on picking up a pair of L30 heads that I found cheap, probably an SDPC intake too.

My questions are:
1. With Vortec heads, is exhaust header fitment the exact same as on a regular sbc? If not, what are the differences?

2. Looking on Jegs, I found Doug's Exhaust headers (p/n 776-D3320) and Y-pipe (p/n 776-D901). I don't need the AIR system (ew), but obviously want the O2 sensor mounts. Does anyone have experience with these headers? Ceramic coated for that price seems like a pretty good deal.

3. Any other words of wisdom for this swap?

Thanks!
Davis

 

Vortec heads have the same exhaust as every other stock small block head. They use a different intake, and require different spark plugs.

DynoDon for headers and y pipe.

AFR as-cast heads will be better and don't require the SDPC intake - which flows like garbage.

Realistically though, without changing or significantly porting the intake, there's only so much you can do.

GD

 

vortec heads may not have the rearmost bolt hole on pass side that stock exhaust manifolds use. running them without that bolt, using stock manifolds, usually isn't a problem. that bolt hole usually isn't used for headers.

second Dyno Dons for headers.

 

What makes Dyno Don's so much better? I know people on this site swear by them, but I'm a college student and it's a hard to justify the extra few hundred dollars when I could pick up a set of headers and a y-pipe for the price of just the headers. And receive them in time to get the car put back together before I head back to school.

Does the stock intake flow any better than the SDPC intake? Otherwise I think it will be significantly cheaper to pick up the SD and the vortecs than to buy a pair of AFR heads.
Thanks for the input.

 

The point is that the Vortec base will pretty much nullify a significant amount of the benefit of the Vortec heads. Without a lot of porting work it's pretty useless. I put a 400 HP aluminum head engine from Blueprint under the Vortec base and made basically no additional performance due to the restrictions. It made 202 at the wheels.

Enforcer as-cast heads are $477 each. The SDPC base is $400 by itself. Stock iron Vortec heads are likely to need a bunch of work at the machine shop to get them ready for use, don't flow as well, aren't aluminum, and don't support higher lift cams without modification. And they can be prone to cracking - which they should be checked for prior to use.

Dyno Don headers because FITMENT. Fitment on anything else is going to really suck. Often quite a bit of modification is required - clearancing and dimpling, etc. Also they are larger diameter than most other offerings, have better build quality, ceramic coating, and thicker flanges.

Price, Performance, Reliability. Pick two.

GD

 

I agree with GD for the most part but this is also on a 305. I wouldn't put those heads on a 305. I wouldn't personally do anything to the 305 except exhaust. And even then, I wouldn't put an exhaust on it if I were planning on swapping to and LSx or LTx later. Waste of money and time.

 

True. But at least the AFR heads will work great on a 350 with a big cam down the road.

GD

 

What makes Dyno Don's so much better?

All the other headers out there have issues, I designed mine to fix all of them.

 

Headers are good and would work on a future motor swap, so go for it. Dyno Dons are the best. 1st class quality and they fit great.

It’s not worth spending time and money on heads for a 305. Put that money toward a future 350 swap.

Maybe put some 1.6 rockers on it. Relatively cheap and easy to do, worth about 10hp.