What needs to be changed to use a fwd 425 in a rwd application? Also i have a two barrel motor i would like to run a four barrel, other than carb and manifold is there anything else that needs switched?

 

There were no 2bbl FWD 425s.

In any case, the only things you really need to change are the oil filter adapter, the exhaust manifolds, the motor mounts, and the starter. Actually, the FWD starter is bolted to the trans and isn't part of the engine when pulled out anyway. Of course, you need to be sure that the accessory brackets all match the water pump and pulleys as a set.

 

well if there were no 2bbl fwd 425's then im good to go. Clearly i don't know much.

 

Are you planning on putting it in that G-body? If so, use the same 2328 motor mounts as are on the 307 now. You may have valve cover clearance problems to the HVAC box. The 307 valve covers offer just slightly more clearance than the 425 valve covers. Yeah, you just use five instead of ten bolts. The repro W/Z exhaust manifolds should work in that chassis. The 307 starter will NOT be strong enough, however. Also, the 307 oil filter adapter bolts up to the 425, but takes the small diameter filters.

 

Yes plan is to put it in my cutlass. I figured it wouldn't clear the HVAC, really only concerned with having a defrost so plan to use something else other than the factory box. I pick it up friday and plan is to disassemble see what i have and then locate parts. Any pointers on that is appreciated. Also concerned with cooling, assuming my old radiator will not cool it, was thinking of larger one as well as electric fans. I have a th350 trans and an 8.5 rear with 3.73 posi rear, will my current driveshaft work? Guy i bought it from said it 442 exhaust manifolds on it, wheather thats accurate or not i do not know. Accessories look like they'll need relocated, to me they look really wide. Are there any headers out there that may work for a gbody? Planned on a double notched crossmember and dual exhaust. Suspension.......front springs need to be beefed up? Im at factory ride height and would like lowered an inch or two, so maybe my wish will be granted.

 

Soft springs crushed by extra weight is not the same as stiff, short springs giving the same static ride-height. The difference is not apparent when the car is parked, but there's a world of difference "on the road".

You'll want to get a proper, PERFORMANCE alignment of both the front suspension, and the headlights if you're changing ride height.

Increase the braking power, too. I'd want 11" drums in the rear, and "something" better up front--larger rotors will need different steering knuckles; but perhaps merely upgraded pads and calipers would work for awhile. Especially if you can find upgraded calipers that would work with the next-stage upgrade to the rotors and steering knuckles. I don't know if that's a possibility or not.

 

The difference in weight between a windowed 307 and a 425 is somewhere between 50 and 100 lbs. If the 307 has an aluminum intake and the 425 is iron, that difference will be on the high side, maybe a little north of 100 lbs. You'll also need a larger radiator, which adds weight, and also a TH400 or a seriously reworked 200-4R. If you're removing the A/C, that takes weight off the front end. At the end of the day, the difference won't be a great as you think. Sit on a front fender - I suspect that will give you a really good idea of the final ride height.