Ok, I have an 89 5.0 with a 4barrel carb no it but want to put fule injection change to fule injection. My question is ... did they change something (the heads (wedge vs 90 degree) or something like that?) that would prevent me from using an 86 intake on 89 gt40 heads? I'm not sure why I thik this but am having a hard time finding a definitive answer. Because this is not directly Maverick related I don't think it is interchange material. Any help or more clues would be great.... Thanks, JC
Simple Thanks That's what I needed to know. Any tips would be nice too. I'm reading other discussions right now but I'm lazy too. If I have a donor car what else would I need for the swap? Probably nothing but tools...., I also plan a 5 speed swap from the same car. What might I need to add besides tools? Thanks for the earlier quick response, JC
nevermind I guess I'll wait for an 89 or better. I found this post and perhaps it will be a while longer before I get to these projects at least the efi.... "It is worth swapping in the EFI but it isn't all that straight forward. I don't know if you are aware of this so forgive me if you already know, but the 86-88 stangs are speed density meaning that the computer calculates the proper amount of fuel to "squirt" into the engine. 89-and up use mass air which squirts fuel into the engine based on the amount of air that passes through the mass air meter. You can't modify the speed density without modifying the computer as well. It will dump in the same amount of fuel regardless of cams, intakes etc. On the other hand, mass air can be modified, to an extent, without changes to the computer. Of note, mass air was introduced in california in 88. It is fairly easy to convert speed density to mass air especially if you are keeping things basically stock. The stock mustang injection parts are quite cheap and can be found on ebay or the mustang corrall. I have attached a pic of the manual I used to do the swap. Well worth the 5-10 bucks."
fth73, that was my quote and it is basically correct. However, I believe bluegrass stated that speed density is certainly acceptable and in some cases preferable. I agree that it depends on the application. With that said, do NOT use any 86 heads, intake or pistons for any modification if you can avoid it. The 86 motors do not have valve reliefs and the 86 intake and heads are the most restrictive of all the efi parts out there. Go with 87 and up and use either speed density or mass air. Also, use HO parts if possible. Other models with 5.0s use smaller throttle bodies and different firing orders among other things.
