Hey guys. Helping a friend with unknown history 91 foxbody. The engine has a factory double roller and if I remember correctly roller lifters but runs like crap on HO firing order while runs much better on non-ho firing order. I found a pic i took when putting factory lower on. Can you tell?
Could be either at this point after So many years and owners but I've only seen e7 heads with that hole above the egr port at the intake face on truck 302's and many years had a double roller and hydraulic lifters.
Spin it over by hand like you where setting stud mount rockers and see what the valves are doing or feel for compression out of the spark plug holes, should be pretty clear if its ho or non ho firing order.
Thanks for the reply. I took this pic when I installed the lower and upper from a wrecked gt. I am worried though the fuel injectors harness might not be wired properly. I am trying to find a wiring diagram for a non ho inj harness to compare