72. BradmobileII427:4.200 bore, 3.850 stroke(427 cu.in) 12.8:1 compression ratio, Full ported Edelbrock Heads 2.100 and 1.625 valves. Torker intake worked over by Donny Schmidt (Kenosha). Roller cam ground by Mike Jones (NC).660 lift, 257/261@.050, 109 LSA. 950 CFM Holley worked over for E85 Jets 95 primary, 106 secondary. We lost a little power with the Dominator in the picture. Jim Landis Headers. 643 HP at 6300 rpm, 592 #ft torque at 4900. I will post up the curves and stuff as soon as I get them.
Email from Brad: This is the dyno run that produced the best result. Some repeats of the same tune up showed 1 or 2 less HP and torque, but the battery voltage had dropped to 10 v, so I will count the one shown below as the best (13 v). There was another one that showed 643/592 with this tune up. 4.200 x 3.850. 12.8:1 CR. E85. Jones solid roller cam in at 106 ICL (LSA = 109), lash .018/.019 hot, carb was 95/106 jetting, 6.5 PV. HVH 1” combo carb spacer. Landis 1 7/8” headers. Booya. Thanks for your help Rick.
57. MN401: Street 401 wiith 750 dbl bmpr, Torker intake,'74 heads and the compression ratio is 9.5:1. Minimal porting was done, just the exhaust ports. The cam is a Isky 280HL. 224/224 @.050, .490 lift, 108 LS. It ended making 380 HP @ 5200 rpm and 430 #/ft torque @ 4100rpm on 91 octane Sunoco. Very interesting to me that it basically made the same horsepower and torque as Fast401's dual quad 10.2:1 engine with the same exact cam. www.ifsja.org/forums/vb/showthread.php?t=151504
I bet it would be close to 400 HP. We had to jet the 750 carb up 4 jet sizes and it was still on the lean side. I am thinking with the same cam, 9.8/10.0:1 compression ratio, and a 850 Holley would get the 400 horse.
Interesting to me that this source en.wikipedia.org/wiki/AMC_V8_engine lists the stock 1971 401 with the 9.5 Compression ratio at 330 Hp and 430 #/ft of torque. So with a bigger carb, bigger cam, better intake and better exhause we made the same torque and 50 more horsepower. Hmm, I wonder if the they rounded up their numbers a little..
I was a consultant on this one. A local guy rebuilt a 304 for a Gremlin with some help from me and my machinist. They dynoed it primarilly just to break it in. A nice reference point to get some numbers. 304 + .030" over bore. 8.5:1 compression ratio. stock heads with bowels opened up. Edelbrock Performer intake, 500 cfm Edelbrock, stock exhaust manifolds, log style on pass side. Comp 268H cam. 2015-05-04 15_31_07-HPTQ-397 by Rick Jones, on Flickr 2015-05-04 15_33_20-DATA-397 by Rick Jones, on Flickr