GT40P head swap problems....

03machone

New Member
Nov 21, 2010
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I have recently done a GT40P head swap motor for my 69' mustang, and I can't get it to start. The heads have the stock springs and rockers, I had to get longer pushrods for the Hyd. flat tappets (5/16,6.9"" TFS) My cam specs are as follows: SAE DUR. ******** Cam Lift
Int. 300 Exh. 306*********Int. 311 Exh 325
.050 DUR.
Int. 224 Exh. 234
The guy that built and assembled my shortblock said he degreed the cam 1 Deg. Advanced. I have spark, I have tried the 351w firing order, I have tried 10Adv-10Ret timing on my crank/ignition timing. It seems to get closest at 3deg. advanced on crank, but it sounds like it is being choked or something. It starts to fire a little when the sarter is ingaged but as soon as I stop turning it over it quites. I also have fuel getting to the cylinders. The only thing I can think of is maybe the valves aren't opening enough? Any insight would be great thank you.
 
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it has to be at #1 tdc on the compression stroke. put your finger over the spark plug hole while someone bumps the starter over until the pressure pushes your finger off.

Absolutley correct! It sounds like the dizzy is off to me! Also, happened to me one time, during a head swap,The TPS randomly went bad and peggedt out at 5 volts shutting down the fuel injectors. Highly unlikely that this is your problem, but it's a quick check!
 
Well, I got my induction timing light out and it turns out i just needed to retard the distributor. I knew i had the NO.1 on the compression stroke because i was checking it with a feeler. I just didn't think my distributor needed to be turned so far to the left. Its a brand new motor and the first time i started it, it has been a 3 month build and I coudn't be happier right now. :nice: Thanks for the posts, now on to the T56 & 8.8 swap. :D