From what I know I have a stock cam and engine in my 1987 Mustang. I currently run about a 13.9 in the 1/4 mile with the few mod's that I have done. I am interested in bolting on some roller rockers. What type of roller rocker would give me more performance gains, 1.6's or 1.7's? What brands bolt up to stock heads under stock valve covers the best? WIll I run into any problems with my speed density setup? Thanks...
Higher ratio rockers will give you a couple degrees more duration (negligible difference) but more importantly more lift.
I built a purposefully mild 351 for a heavy car for street and lots of hiway miles.
Needed to retain somewhat decent mileage, and a relatively low rpm curve -
didn't want high rpms for either the torque peak or hp peak.
So, also being on a budget, bought a good used lo miles stock HO cam and
added 1.72 rockers for more lift which gives more torque at the same
rpm range. Lift went from .444 to .477 which primarily gives more torque
in about the same rpm range.
You'll need pedestal style rockers for your stock heads. Crane, Ford, Comp, and a number of others make them. You'll likely have to remove some of the baffling
under your stock valve covers, and you could also use a thicker gasket to help
a little.
I don't know about the sd setup - I converted mine to MA b4 I swapped engines.
I've heard of guys running cams like the "Baby Crower" with good results in sd
engines, which mainly has more lift, so wouldn't think you'd have any significant
problems with the sd setup. You'd still be keeping the wide lobe sep angles
which is critical to the sd running properly from what I've read. With roughly
7% more lift, I wouldn't think it would give a problem.
1.7's on a mildly modded motor will probably net around 8 peak hp. The only real thing I would be worried about is valve float. If your valve springs are weak, the 1.7's will make 'em float like crazy and you will actually lose about 10 hp. You might want to do the springs too.
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Cardinal Red '88 GT 5 speed, Cobra Upper/Lower, Dynomax complete Super-Turbo cat-back system, Turbo Coupe Rear 10" discs, 3:73 gears, SN95 Master Cylinder, Summit Racing adjustable proportioning valve, Spec Stage II kevlar clutch, steeda adjustable cable/quadrant, 73mm front calipers, P.A. Performance 130 amp alternator, 99 Contour Electric Dual Fans, Battery relocated, rebuilt 91 T-5, Mass Air conversion
Valve float is not something I want to deal with. I really didn't want to go through the work of taking the heads off and changing the springs. How about the 1.6's, is valve float a common occurence? What type of perofrmance gains can I get from 1.6's?
I just installed 1.6 roller rockers and it is much quieter. I also noticed slightly faster accelleration but when you are dealing with possible 10 horsepower or less it is hard to tell a difference.
If you have a stock cam I think you can get away with 1.7's or 1.72's, but if you have an upgraded cam and stock springs, I would definately stay with 1.6.
Just FYI you don't have to remove the heads to change springs.
There's a reasonably priced tool for compressing the springs working
totally from the spring side of the head.
Still, not the simplest task as you're dealing with preventing the
valves from dropping (just rotate the motor so the piston is up
in that hole) and especially getting the little locks out and back in
can be "fun"
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89 Linc Mk VII LSC mass air w/A9P; 95 351 Lightning shortblock, 1.9 Ebrock heads, GT40-351 lower w/match Explorer top, 70mm mass air w/30 lb inj's, TF Stage 1 w/1.72 Crane rockers, 1-5/8 ceramic shorties, 2-1/2" Dynomax catback, 3 row rad, Ford blue hoses & wires, remote trans filter & plate cooler, 2500 lockup stall, beefed AOD, shift kit, 3:55's, 96 Cobra 17x8's, 99 Stang bolt on scoop. 4R70W, 2600 stall, Baumann TCS soon.
I have done head work before, those valve locks are a pain in the a$$. Not sure if that something I want to get into at this point. However, I am going to look into that tool. Nice to know something like that is out there. Thanks
Roller Rockers 1.6 or 1.7, What is better?? 
