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Discussion Starter · #1 ·
I am about to pull the trigger on a set of TrickFlow 18° heads, but I want to make sure I know how much a pair of 18° headers are going to cost. Can I just modify my current 23° Super Comp headers by cutting off the flange and changing to a Stahl flange?
Who makes 18° headers for the third gen Novas?
 

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Discussion Starter · #3 ·
Really appreciate the Dynatech link. The 3/4" to 7/8" step design in ceramic coating would work well for me, and the price isn't too crazy. The ones listed in racingjunk look like they would stick out from the head too far for the Nova.

I am slowly getting my build finalized in my head. Right now I just have a used Dart Little M block (4.125" bore w/ 350 mains) and 6" Oliver rods. My plan is to bore it to 4.155" (the bores are acceptable, but might as well start out fresh), buy a 3.875" crank, buy a set of Trickflow 18° heads that I am currently looking at, and then spec out some pumpgas / nitrous friendly pistons plus a solid roller cam grind. My desktop dyno program estimates mid to upper 600s FWHP, depending on how much duration I pick for the cam. This will be a nice upgrade from my current 406, which probably is at 500 fwhp or slightly less.
 

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A motor like that needs some 1 7/8" primaries to start with. Maybe do a stepped header 1 7/8" to 2" with a 3.5" collector. Check with Lemons headers out of Paso Robles, Ca. He builds alot of heads up street car shootout type stuff. Nice work and reasonable prices.
 

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Just for FYI. I am reusing my 23* step header's. I am going to use some(forgot what you call them)adapter's that change the bolt pattern to the bolt pattern on my bowtie head's. I checked and they are different.
 

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I agree with 6Nova4. Lemons makes nice stuff that fits and you can get to everything. I had a set of headers built by Tom Dawson out of Lake Perris, on my 70 nova. I was running a 421 inch sbc with 18* Edelbrock heads. They were 2 inch stepped to 2 1/4 with a 4 inch collector and collector mufflers. We thought they were going to be too big, but they worked fine.
 

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Just for FYI. I am reusing my 23* step header's. I am going to use some(forgot what you call them)adapter's that change the bolt pattern to the bolt pattern on my bowtie head's. I checked and they are different.
Are you using the Nimac HS7 adapters?
I am in the same situation with some Bowtie 363 18° heads, and in a real bind.
I have a set of Hedmans Fenderwell 1 7/8 that have been coated, and I've been told that once coated they cannot be welded.
Otherwise I would put a set of 18° flanges on them.
I have a set of the 18° to Stahl adapters but my headers are the 23° Stahl pattern and not the spread port pattern.
It looks like with a little bolt hole modification and porting of the adapters they would be real close.
Have you tried them yet?
 

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My desktop dyno program estimates mid to upper 600s FWHP
My 410" makes 615 h.p. with just under 12-1, and a little 260/268-.615/.617 roller. I'd think with 18° heads you could make close to 700 without too big a cam. My Jack Davis headers are 1-3/4"--1-7/8"--2.00" w/3-1/2" collectors; Jack makes them for 350 stock eliminator applications..he likes em big, but I opted to stay with the smaller ones.
I don't see why the flanges couldn't be changed; if they are coated, grind off the coating before welding.
 

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as said before the headman spreadport will work. we used a set of headers that were on a old w/s car and put them on the l/s car . the w/s car was a 18 deg and the l/s was a 23 deg.
 
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