Superformance headers

[427supr]

Will Edelbrock Victor Jr. heads bolt up to the Superformance 402 headers? I am thinking of building a 408 stroker, with the edelbrock heads. I was told the 402 header was built for the AFR heads. I am not sure if the edelbrock and AFR heads have the same size raised ports.

[RedBarchetta]

I've been told no, but maybe someone else can chime in to confirm. I believe the ports on the AFRs are raised more and you get an even worse match-up than what the factory header already (doesn't) provides.

-Dean #747

[CHRIS DAMSCH]

427 supr
Not sure if you are looking for an older set of spf headers or not. If you are I have a set off of 1454 that are not being used anymore and might be for sale.

[greg schroeder]

The headers that were on my car number 2040 covered 1/3 inch width of each exhaust port. The Roush engine had AFR 205 heads. I'm not sure if there are new headers that are wider though. I put on some other headers. Here's the old header and what I replaced it with from the Olthoffs.


I'd like to see the "402" headers if anyone has a picture of them off the engine.

[ken swart]

I don't have photos, but I ordered spf 2489 spring 06 and specified a 351W.
The car came with the same headers as the top header in Greg's photo.
They match up nicely with the AFR 205s on the Keith Craft 427 stroker.

[Badger]

The stock SPF 402 headers were designed to use with AFR 185 heads. If you plan on something larger you'll need to use the 205 AFR heads. The 205s have a slightly raised port so the stock SPF headers mask the top end of the port. Also the primaries are a bit small. Fine for a 402 or smaller but inadequate for something larger. Badger

[SPF1061]

I am no automotive genius, fer sure....but I have had both of the headers shown in the photo on my Roush 427R. The top ones match up much better with the exhaust ports on the 427R heads and it would seem a no brainer that they would be the best choice. My real world experience is that with headers, as with carburators, bigger is not automatically better. On the dyno, the big headers produced almost exactly (no more) hp up top @ 6000 rpm. We had to richen the jets up several numbers to get this result. The big difference was that they gave up more that 40 to 25 ft /lb torque throughout
the rpm range until well over 5000 rpm, then they equaled out. Seat of the pants. The big headers seemed to wind up faster. They seemed to go from 4000 to 6000 rpm almost instantly. A very nice open unfettered feeling. However, again, down low, they really lacked the seat of the pants instant freight train up yer a$$ feeling of the small headers. At the drag strip, I lost nearly .2 second off my et with the big headers. Bottom line, FOR ME, the smaller headers were the better choice. If you have a really high rpm motor that twists to 7 grand all the time, the big headers would be awesome. If most of your driving is in the under 4000 or so with an occasional charge to 6000, the smaller headers might be a better choice. This is just one guys experience. YMMV. Have fun!
Steve

PS - my headers feed into Stainless Specialties 3" through mufflers - not the stock SPF ones. Just so you know.

[RedBarchetta]

Originally Posted by SPF1061

PS - my headers feed into Stainless Specialties 3" through mufflers - not the stock SPF ones. Just so you know.

Ditto.

Even if you open up the headers, you HAVE to address the restrictive factory muffler to benefit. Some have done both (Greg), and he optimized the entire car to run a 10.70 @ 132. So you can make great power with the 427SB and the better headers, but you have to optimize the carb and then upgrade the rear-end or all that new found power will spit half-shafts. Greg's build, to me, is a text book example of how you take a basic package, optimize it in the right spots, and run high 10's on street drag radials all day long.

-Dean #747

[427supr]

I have a early Superformance. One of the first batch to come to the states, #046. I just want to know if my stock headers will bolt up to the Edelbrock Victor Jr heads, or will I have to go to the 402 header. I am running GT-40 aluminum heads now.