Roland-Rather than exploit some nice hi-po heads I would suggest
purchasing a set through PAW. For about $4-500 you can get small
chambered heads with enlarged valves, porting, and solid screw-in rocker
studs. I've had great success with htese !!
The Happy Mechanic-Chris
On Tue, 16 Apr 1996, Roland Dudley wrote:
> I received lots of responses to my should-I-have-larger-valves-installed
> question. Thanks to all of you who took the time to respond to that
> question and beyond. Recall I was asking so that I could decide on
> whether or not to have the valve cut-outs in my flat-top after market
> pistons enlarged. A couple of people suggested the obvious: have the
> cut-outs enlarged and worry about the valve question later. That made
> so much sense, I got on the phone right off and gave the okay to my
> rebuilder to do just that.
>
> As for the larger valve question, as several people pointed out,
> unmodified HiPo 289 heads are getting hard to come by; better to screw
> up some less rare/valuable set of heads or go after-market. I'm keeping
> the unmodified heads as is. The other set I have already has larger
> valves and has had some chamber and port work done to them. Assuming
> they are usable, I'll keep them around for swapping with the stock heads
> if I decide I want a little more power later. Or maybe I'll start with
> them and fall back to the stock heads if I don't like the results.
>
> Several people suggested replacing my street radiator with an after
> market aluminum rather than having the original recored. A couple of
> thoughts on this: 1. This means a mix of cast iron and aluminum, which
> means the potential for damage due to electrolysis. In this case, the
> aluminum is the metal that would suffer the serious damage. I've
> already experienced this to some degree with the aluminum water pump,
> the thermostat inlet and an aluminum Tee. The Tee is beyond salvage.
> 2. Some early street Cobras did have aluminum cross-flow Harrison
> radiators and the spun aluminum header tanks. Shelby dropped these
> early on because they didn't hold up very well. I'm assuming there was
> a reason for this then that might still apply today. My plan is to use
> distilled water and anti corrosion/lubricant additives rather than
> glycol based antifreeze to improve cooling.
>
> Here are a few other things about the engine's setup I didn't mention in
> my original post in case anyone is curious:
>
> solid lifters
> hi-riser aluminum (original Cobra) intake
> 715 CFM Holley
>
> Thanks again,
>
> Roland
>
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