[stangowner8687]

sorry if this is already a sticky or been posted elsewhere i am just in a hurry, and my quick browse found nothing. if you guys don't care to post. i would appreciate being pointed in the right direction. heres my question


i have an 87 GT and 90 GT not sure of compression diff. but my concern is the LX heads what kind of loss would come? its so hard finding the HO motors and i would like to exp. with some porting and forced induction. can the LX head be machined into a GT or no? if so what kind of flow would i need? i am using the harland sharp R.rockers.

 

[UnexplodedCow]

You can't use an LX head on an HO bottom end without changing to LX pistons, or else you machine the LX combustion chamber into a hemi, which is a bit of a waste since it's a small port, small valve design. The compression between 87 and 90 are the same. The only difference will be the 90 having a roller cam setup.

The LX head could possibly be machined, but the intake manifold is different (you'd have to use a 2nd gen intake) than the HO type.

 

[stangowner8687]

eah, the intakes i wouldn't think to be damaged if the head warps/cracks, or anything else that would ruin a head. but just wondering how many donors would be possible. but if i understand correctly the LX is not possible unless the pistons are also swapped out, or can it be machined to match? i have yet to really rip into my motor yet. as for the roller cams. is there anyway i could convert my 87 to roller cam or is it not so simple?

 

[UnexplodedCow]

You also need the LX intake...it will NOT bolt to an HO head..bolt patterns, gaskets are different, water port is different. The bolt patterns are close, but it's really the port location that makes everything not work. I've tried...believe that.

 

[stangowner8687]

that sucks. in otherwords it would be like de-grading the motor from EFI to TBI ok, so i guess i i can only get Escort GT heads. now lets say i destroy my block, now i should be able to use LX blocks right?

 

[UnexplodedCow]

LX and GT blocks are identical in every way. They use all the same parts, except for pistons. The difference between HO and CFI is in the head/intake.

You could also look at using a 2nd gen intake for the CFI head, but you're still stuck in the small port/small valve land.