Going to be building my 5.0 this winter for a 89 Fox. I was wondering if any of you have a tried and true formula for making 400NA reliable/bullit proof HP out of these motors.
I guess all you have to do is pick up a 5.0 mag or MMFF mag and read. Many combo's out there making that power. Probably not with all the accesories attached but on an engine dyno they do. http://www.airflowresearch.com/ford_dyno.php
look at think link it should give you a few idea's.
I good H/C/I package with a matching T-body, Mass air sensor, injectors, exhaust, and CAI set up will make 400HP. This should make over 300RWHP, which is great power with a stock bottom end fox body. 5.0 Mustang mag has an ongoing project, which by now I think they have added a blower and nitrous. ALL ON A STOCK BOTTOM END!!
Add TRW forged piston rebuild kit from summit, (10.11:1 with 58cc heads) headers, ported 351W heads, ported Performer RPM, 650cfm carb, Speed-Pro CS195R cam, windage tray, low tension rings, and Volia! 401hp. Also, a set of cleaned up AFR165s and a custom Comp cam are worth about 25hp more (was looking at 419hp without cleaning up the heads).
I think for road racing your best idea would be to bore it out .030. Buy a nice balanced eagle rotating assembly (All Forged 331). The idea here is bulletproof. A main support and windage try aren't a bad idea either, along with a big oil pan.
I would aim for around 10:1 with stock combustion chamber size. Either AFR 185 or TFS 185 heads with the upgraded valve spring packages. (Think bulletproof) I would have these gasket matched to a fel pro 1250 and run a trickflow track heat intake, performer RPM, or systemax intake manifold...also matched to the 1250. As for the cam...you could go with XE276HR or the TFS stage II. Many here will tell you that a custom cam is the best...and they are right...but you could make 400 hp without one. Comp cams pro magnum rockers (1.7's). Gasket match the heads to the proper header gasket for a nice set of longtubes. Run a set of 30 lb injectors a Pmas MAF and an accufab 70mm tb.
That would make one hell of a combo and easily put you over 400 fwhp...and around 325-340 rwhp. A custom tune would be necessary. Good luck man...sounds like fun