unimaginable87

I just got a 302 for my 87 mustang but it isn't high output. i was wondering if i can put in roller rockers like is in the high output with out putting in alot of money. Or should i just buy a high output 302. thanks. J.R.

88blackCONvert

Sure you can put em on, and maybe gain an extra pony or 2, but your gonna have a hard time getting your engine to run like a HO 302. The cam is different, and possibly have different heads on the regular 302. I would save some cash and get a HO, or just rebuild the one you have and use the HO parts, or even upgrade (better camshaft/heads). I promise you'll be happier if you do. The rockers are gonna cost around $200-$300 for a nice new set, and will be a nice addition to the top of your engine, but you won't see any great difference by just swapping your rockers out, and you may run into clearance problems if you decide to go with a bigger rocker arm, soooo i say rebuild!!

5.0stanger

Just buy a HO. Cam is different, compresion is less, heads might be different. I would keep looking

Ecstasy

so less compression is better then higher compression?

5.0stanger

Depends on what you want in a motor. If you want to use a power adder lower is better. If you want a proformer w/o a power adder higher is better. Just don't want to go to high for a dd b/c it will require premium gas.

Ecstasy

i have to put premium or ill sparkknock wetf that is, so maybe my compressions already bumped? wtf causes sparkknock anyways?

ckyguy68

advanced timing, too high compression with low octane.

spark knock is actually preignition. the air fuel mixture in the combustion chamber actually ignites on its own, before the spark plug fires.

l mixture in the combustion chamber actually ignites on its own, before the spark plug fires.