Join Date: Jul 2017
Location: Yadkin valley, NC
Re: Low rpm 390 stroker advice
I went through this with mine three years ago, similar goals. My car is also 4400# and I have 3.00 gears.
I went with an RV type hydraulic roller cam, PQ adjustable rocker set and custom length push rods. I went through several sets of lifters before finding one that worked- Lunati Voodoo. The roller gives faster valve lift so more area under the curve; basically turning a 390 into a much larger net displacement.
Compression is 9.7:1 and I use 93 octane pump gas with no problems whatsoever.
Follow Rabotnik's advice on oiling modifications. He says use 0.060 - 0.090" restrictors to the heads. Go on the low side.
I went with a FAST throttle body fuel injection setup which necessitated the single plane intake, so keep that in mind if that is on your future wish list.
I have Sanderson headers- the only brand I found that would fit my unibody car with the fat spring towers. With your full frame car you have more options. I also have 2.5" dual exhaust, H pipe, and Borla mufflers. I had Magnaflos but they droned at speed so I changed them out. I also have Hushpower glasspack style in the rear acting as resonators. The car is quiet at idle but roars when you push the throttle.
The car isn't a rocket ship with the 3.00 gear but it is still very quick off the line. My ass-dyno tells me I'm at about 50HP over the stock 300.
My most recent mod was an AOD. At 70MPH the RPMs drop from 2700 down to 1800 and I have plenty of torque to climb moderate hills without downshifting. On two lanes I can tool around at 1400 RPM which is great fun.
1964 Thunderbird 390 V8, AOD, F.A.S.T. EZ EFI 1.0, Victor intake, MSD Ignition.