Is it possible???

[racer11]

Just curious about this one. My buddy had a 420, 23* modified engine built and he told me his engine builder said it had right at 700 HP. I was thinking that is a little to much for the heads being they are the brodix track 1x. Let me know what you guys think or know from experience. Thanks in advance.

[Egoracing]

Just curious about this one. My buddy had a 420, 23* modified engine built and he told me his engine builder said it had right at 700 HP. I was thinking that is a little to much for the heads being they are the brodix track 1x. Let me know what you guys think or know from experience. Thanks in advance.

What engine block? Stock GM block will come apart with anything over 650hp and it may do it at 650.

[SLM98]

Sounds like the builder has the correction factor on his dyno jacked up.

[racer11]

It is in a dart litlle m block. I was thinking the same thing about the dyno but wasnt for sure. Keep the thoughts coming. Thanks for the input.

[bushracing67]

nascrap makes 850hp with a 358... im sure it would not be out of the question to get that with a 415+", you could throw money at it til it made the power numbers that you are talking, but is it driveable ? too much carb and too much cam will make power on the dyno but might suck at the track

[hpontap]

A good head guy can get some impressive numbers from the old Track I's.

If its just the big numbers you are looking for, a better set of heads would produce more but for your average guy on a short track the Track I's will work well.

Just built a 421 SHP block, 14.5-1 , 260'ish custom roller with some worked Track I's on it. Very driveable and 680hp @7,600 rpm on gas. An easy build.

[Egoracing]

nascrap makes 850hp with a 358... im sure it would not be out of the question to get that with a 415+", you could throw money at it til it made the power numbers that you are talking, but is it driveable ? too much carb and too much cam will make power on the dyno but might suck at the track

No way to compair RO7 engines to a 23 degree motor, and it is more towards 900hp with 358.

[parrot69777]

Nascar was making 740hp on a 358 with 18 degree heads 15-20 years ago and IMCA lates model are making over 600 hp with restricted track 1 heads/intake manifold on a 361 cubic inch rule, with 10.5:1 compression.

If those heads have any porting or have been cnc'd and with the proper intake, custom grind cam, etc. on a 420....sounds pretty reasonable to me.