1 7/8-Inch Long-Tube Hooker Headers With the 1 ¾-inch headers making the Smeding act screwy, we could only imagine what would happen with the big-daddy 1 7/8-inchers. These headers did not come with collector flanges. We put the Hookers to the Edelbrock RPM Performer heads using the favored Fel-Pros and pulled the handle. This time the power numbers danced around like they did with the 1 ¾-inchers and we immediately checked over our previous measurements.
As it turns out, the larger the tube diameter, the more a broad tube bend is required. This in turn lengthens the headers, and in our case resulted in another ¾ inch of total tube length. Again, we felt that this addition combined with the same previous engine-exhaust-wave tuning had something to do with the up and down power curve. If we had ran high-flowing cylinder heads, a huge camshaft, and maybe even a power adder, these big pipes would have shined from 5,500 rpm all the way up.
RPM; TQ; Diff.; HP; Diff.
3,000; 430; +8; 246 +5
3,100; 436; +13; 257; +8
3,200; 438; +16; 267; +10
3,300; 436; +14; 274; +9
3,400; 433; +10; 281; +7
3,500; 433; +8; 288; +5
3,600; 435; +5; 298; +3
3,700; 438; +1; 308; +0
3,800; 442; -2; 320; -1
3,900; 446; -2; 331; -2
4,000; 449; -4; 342; -3
4,100; 453; -5; 354; -3
4,200; 456; -6; 365; -4
4,300; 458; -7; 375; -6
4,400; 459; -7; 385; -5
4,500; 459; -8; 393; -7
4,600; 459; -8; 402; -7
4,700; 457; -7; 409; -7
4,800; 455; -7; 416; -6
4,900; 452; -7; 422; -6
5,000; 449; -6; 427; -5
5,100; 445; -5; 432; -5
5,200; 440; -6; 436; -5
5,300; 436; -5; 440; -5
5,400; 432; -2; 445; -1
5,500; 428; +1; 448; +1
5,600; 422; +1; 450; +1
5,700; 415; +4; 451; +5
5,800; 407; +4; 450; +5
5,900; 398; +5; 447; +5
6,000; 390; +5; 445; +5