has anyone used a 7" 3g on their idi? received a free one like new. will the factory belts accept the extra adjustment? i know a 8.25 is whats usually used for this but the price is right! if any major difference i guess drop the two belts by 1" to accommodate the difference? thanks for any help,i only have the truck so it cant be down more than a day [1990 f250 7.3 idi].

 

Well, as long as you don't destroy the original mountings, you should be able to try it out and see what works, then drop the old one back in until you have more time.

 

I used the 7" 3g for a few weeks cause that's what I had on hand, main problem was the belts. No matter how much I tightened them, while she was running the belt slap kept the belt rubbing the lower mounting bolt. It ended up wearing the belt down pretty quick so I did eventually swap out to the 8.25", and that's worked great for me. I never tried smaller belts tho, that may be a worth while option and could solve the problem.

 

thanks MONTE97Z, ill check out the belt slap, it might work since in my research i have the ambulance fan belt which is 1 inch shorter+-.

 

Nice. Hope you get it to work. It's definitely worth the conversion. I'm very happy with it and any time you get the parts free it's that much sweeter. Good luck

 

I went with the wider ears because that's what everyone says fits, but it does look like the narrower ears will fit. I would prefer a more compact setup so curious if the 7" spacing works, please let us know.

 

still waiting to install, all parts gathered, just waiting for time to do it, drive a big truck so schedule is really flaky.

 

FINALLY GOT IT INSTALLED, IF YOU SEE THIS "CADUNKLE" NO REAL PROBLEMS, HAD TO MAKE A SLIGHT RELIEF GROOVE WITH A DIE GRINDER ON THE FUEL FILTER TOWER TO INSURE NO RUBBING FROM ONE OF THE THREE BOLTS ON THE ALTERNATOR CASE[DOWN BY THE PIVOT]. HAD NO BELT SLIP,EVEN USED OLD BELT FOR NOW DUE TO LACK OF TIME.[ I DID PUT A 1.5 SECOND"SOFT START" REGULATOR IN.] NEXT DAY OFF MAKING UP NEW MAIN BATTERY CABLES TO COMPLIMENT THE UPGRADE.

 

I also used a 7" 3g. Only issue I had was it was difficult to set the belt tension, ended up using a bolt in the mounting bracket and a c-clamp to tension it. No belt slap now and 14.8v.