What headers are being used with the AFR big block heads and how are the fitment issues. anything else to look for?. oil pan clearance, spark plugs, wires, starter, etc.. thank you.

I believe the AFRs have a .375 raised exaust port so take that into consideration.
You didnt state what you application is , so here is what I'm running. AFR 335s on a 540 in a 70 SS Chevelle. The headers are 2 1/8 stepped to 2 1/4 to a 4 inch collector. They were made by Lemmons Headers in California. They look and fit great, but being that big of a header they have two tubes that go around the frame. On the drivers side I had to cut way up into the inner wheel well. I wasn't too happy about that, but being a street/ strip car, I guess its ok. Also, they came in individual pieces. Here is a pic that may give you an idea. That one tube comes up kinda high!!
http://www.chevelles.com/showroom/70SS540/chevemotor.jpg

I've got AFR 315's on my 540. I'm using Jet Hot coated Hooker Comp headers with 2" primaries (I think 2455s). I installed my headers when I did the motor so it was easier. The driver side came in from below. I think I found it easier to do the passenger side from below too. Oil filter clearance is a little tight with my kicked out Moroso pan, but still doable. Overall I was quite pleased.

Another guy said he had problems with his car but it has a/c. I have a 70 no a/c, no p/s, with 2455 headers and will be installing the afr's in a few months . they do look real nice tho. nice look there 70SS540.

Thanks 70 GMuscle! You'll be happy with the AFRs! Hey Ben70, I was originally going to run the 315s on my 540. At the last minute we changed cause I wanted over 800 hp. I'm curious as to what your motor configuration is and numbers if you have them. Thanks, Nick

Originally posted by 70SS540:
Thanks 70 GMuscle! You'll be happy with the AFRs! Hey Ben70, I was originally going to run the 315s on my 540. At the last minute we changed cause I wanted over 800 hp. I'm curious as to what your motor configuration is and numbers if you have them. Thanks, Nick I went with the 315s per some recommendations I got on this board. I think Wolfplace and some others along with Shafiroff (where I bought the shortblock and heads) recommeded I go with the smaller (LOL) heads since my car would primarily be a driver. My configuration is not ideal (the intake manifold should really be a single plane--but I wanted it to fit under my factory C.I. hood, hence the Weiand Stealth).

Here's what I have:
Merlin III block
Eagle Forged crank
Eagle H-beam rods with L-19 rod bolts
SRP forged pistons
Speed Pro Moly rings
AFR 315 CNC ported heads
Comp Cams Solid Roller: 254/260 @ .050, .660 lift
Weiand Stealth Dual Plane
BG Race Demon 1000cfm
Pertronix distributor
Moroso oil pan
Stewart Stage 2 water pump

Unfortunately I've only run the motor on my test stand so no numbers. I have it in the car, it should be on the road in the next couple of weeks--weather permitting. :D

I have the 2455 Comps on my 315 AFR heads. No way to get a regular plug wrench on 4,6, and 8.
Looks like I'll have to cut one 1/2"or so to get it over the plugs.

John

Ben70,
You got the right heads! That dual plane could be a choker though. With a single plane, you should have mid-high 700s depending on compression.
Ya, a few of my plugs are hard to get at too. I go through the wheel well on those. Much easier especially since my left wheelwell is now chopped up a bit.

Originally posted by 1970 GMuscle:
Another guy said he had problems with his car but it has a/c. I have a 70 no a/c, no p/s, with 2455 headers and will be installing the afr's in a few months . they do look real nice tho. nice look there 70SS540. That would be me :D Here's a pic of the problem plug #8. I don't know if not having AC would allow me to access this plug or not. The problem may be the headers (hooker 2455)
plugs (http://www.chevelles.com/showroom/SMS/Picture.jpg)

Wow, that is tight, SMS!! I wouldnt want to change that one! My last pipes (#8&6)go around the frame, so it is much easier to get at #8 but I still have to go through the wheelwell.

thanks for the recomendations. I to am building a 540. 70SS540 if you might be able to divulge any info my email is mcgyverracing@yahoo.com
I have a few ideas I'm working on and am looking to make 730 hp at least. was told I should hit it even with a goof up from my short block assembler over at shafiroff. also got my heads from wolfplace. mikes a good man. found him thru different souces on the web. I haven't visited here much in a few years. I had a different name but lost all my info from a computer crash back in 2001 then. thanks again guys.chris

are there any other headers being used in this head swap?. just checked out the lemmons site.

Originally posted by 70SS540:
Ben70,
You got the right heads! That dual plane could be a choker though. With a single plane, you should have mid-high 700s depending on compression.
... Yeah, it's definitely not ideal. My compression should be about 10:1. I originally had a high rise Dart single plane, similar to yours that I was going to use. However, I was worried about hood clearance. Maybe if I can find a decent low rise single plane.

SMS is that plug touching the header tube on number 8. is there wire clearance at all. there is a tight fit on that wire with stock cast iron heads and those 2455. I always heat wrap that wire on my 454.

Well guys, I've been looking at this thread for a few days now and I have realized that other people are having the same problem as I did with my AFR's.(Pics in my signature).

I have some AFR 315 on my 496. I have some small headman 1"3/4" headers (soon to be replaced) from my old setup, running on it now. And, yes it’s choked up.

1st. I ended up using the 3/8 Autolite spark plugs. If you compare the length of them, they are the same size as the Accell shorty plugs.

2nd. I ended up disconnecting the 3 and 5 header tube, pulling it back and holding it with a wrench wedge in between. Then I could put the plug in using a socket and boxed end wrench to tighten them.

3rd. To protect the plug wires. I purchase those fabric plug shields to go around the spark plug wires. I put one wrap of header wrap around those header tubes that the plugs were closest to, also.

Last. I was told that my problem was those Headman headers that I had and a good set of Hooker headers would solve my problem. Now I am glad to see that those problems will still exist on my next header upgrade. I see I will have to do the same thing with the 21/8" hookers I plan to purchase.

70SS50, those Lemons look great in your photo. Props out to ya. For the price of them, they better fit -). Smile.

I run Hooker Super Comps #2265, 2 1/8" primary, on my 540 with the Dart Pro I 325cc heads which have a .400 raised exhaust port. Other than shortening down the length of a plug socket to install/remove #5 plug, there wasn't any real clearance issues.
I don't anticipate any problems when installing the recently purchased AFR 335 heads either which have slightly shorter exhaust port location (.375 raised).
I do use a 90* end plug wires, too.

Originally posted by 1970 GMuscle:
SMS is that plug touching the header tube on number 8. is there wire clearance at all. there is a tight fit on that wire with stock cast iron heads and those 2455. I always heat wrap that wire on my 454. No its not touching, but that plug wire will definitely need a heat shield sleeve on the end! It's the header pipe routing that causes the problems, not the heads. With my A/C, I can't use an over the frame configuration on the passeger side. At least it doesn't look feasible.
Steve

Ya, those headers were a little over a grand before Jet Hot got a hold of them!! :eek: Excellent quality though.

SMS I just realized that the problem plug with the comp 2455 headers and stock cast iron heads is wire number 6. it has 3 tubes by it one of which crosses horizontally. I see no one here has tried hooker super comp headers yet, either size.
I still have time before the install so I will wait and see. Unless I cash out all spare parts I own I can't afford lemons headers. any hooker supercomp users here yet?

BillsCamino, a few posts above is running them! Sounds like they fit pretty good.

how'd I miss it, thanks. I'd love to see a pick of each side head. earlier I did a comparison of the 325 as cast port and a victor jr. square intake and it seems the intake port is raised a lil bit like 1/8 to 1/4 inch on the head with the intake bolted to the head. I will recheck my findings

Originally posted by 1970 GMuscle:
I just realized that the problem plug with the comp 2455 headers and stock cast iron heads is wire number 6. it has 3 tubes by it one of which crosses horizontally. I see no one here has tried hooker super comp headers yet, either size.
... any hooker supercomp users here yet? Here's a pic of the pass side Super Comp shown installed on my '70...
#6 plug is easily changed from above by reaching around to the underside of the pipes.
http://www.chevelles.com/showroom/BillsCamino/70Chevelle2.JPG

Bill is running the 2 1/8" super comps which run one tube over the frame. The 2"(pn#2217)super comps are similar to the 2455's as far as pipe routing.Correct me if I'm wrong.
Steve

thank you guys for the info and pics. Bill I see your car has manuel disc master and manuel steering just as mine does. this is really helping my decision. did you have to ding any tubes or grind frame or control arms anywhere. I understand each car is different after all the years of abuse and/or accidents. frames can get messed as mine once was. how was the port alignment cylinder head to intake. seems these might be slightly raised runner heads. I will call tony mamo next week with my questions I have been taking notes. thanks again, chris