Thread: Dart Iron Eagle Heads

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I'm not impressed with the Dart Iron Eagle 165 or 180 heads. A respected member on another forum has flowed the 180's out of the box at 205 to 210 cfm, only marginally better than production double hump heads. Stock GM Vortec L31's with 1.94"/1.50" valves flow better than either.
L31 flow...
0.100" 70 48
0.200" 139 101
0.300" 190 129
0.400" 227 140
0.500" 239 147
If I were going to use Iron Eagles, I would use at least 200cc runners even on a 350 motor.
If you're on a budget, go to the boneyard and buy a set of casting number 12558062 Vortecs from a '96-'98 Chevy truck with 5700 Vortec motor. Get the rail rockers and valve covers at the same time. Look for a hacksaw blade casting design on the end of the heads. Make a deal with the boneyard operator that you can bring 'em back to exchange them for another set if you find 'em cracked. Take 'em home and disassemble 'em. Take 'em to an automotive machine shop and have 'em magnafluxed for cracks. If they're ok, have the valves and seats touched up and install new seals. Have the shop drill 'em for steam holes....
http://www.gregsengine.com/350to400.htm
Install CompCams beehive spring #26918, retainer #787 and steel locks #601. They will install with no machine work and allow at least 0.550" lift. These springs install at 1.800" installed height with 130# on-seat pressure.

Use KB168 Keith Black hyper pistons (22cc D-cup) with 5.7" rods. (I just love it when I get to type D-cup and enjoy the euphoric recall associated with it). The stack will measure 9.008". Cut the block decks for a block deck height of 9.014" (0.006" piston deck height). Use Fel-Pro #FEL1014 head gaskets
(0.039" compressed thickness with steam holes). This will allow a squish of 0.045" and a static compression ratio of 9.8:1.

Use an Edelbrock Performer RPM Vortec or RPM Vortec Air Gap intake manifold with 750-800 vacuum secondaries carb. If automatic, 2500 stall converter with 3.50-3.80 gear. 1 3/4" long tube, equal-length headers.

Compcams 12-326-4 hydraulic flat tappet cam. 286/286, 236/236, 0.490"/0.490" with stock Vortec 1.5 rail rockers, 106/114/110, installed straight up. Dynamic compression ratio 8.21:1.

RPM HP TQ
2000 153 401
2500 193 405
3000 245 429
3500 304 457
4000 354 465
4500 390 455
5000 414 435
5500 386 369
In excess of 400 ft/lbs of torque from 1900 to 5200. Nice.