Just bought a 94 f150 5.0 and I love it. The 1st engine blew so ended up putting a 84 5.0 302 in there and runs like a champ. But just recently its been sluggish only at 40 mph. This has the polution set up and saw that the cat got bright red before during its test period in the drive way . But that went . A check engine light is on but still wondering on some opinions? Haven't pulled the code yet .

 

check engine light only comes on after I've driven a while.

 

Did you change the distributor gear or the entire distributor when you did your swap?

 

I changed the entire distributor the engine I bought didn't come with a distributor. It Is timed at 10 advanced with a timing light .

 

I changed the entire distributor it is timing perfect at 10 advance on the distributor

 

Pull the code.... The cat should get hot but not glowing red, it may be clogged or you are running very lean which will severely reduce your power and can damage the heads/valves.