Bagpype

I have a 1991 Convertible C4. Before I bought it it was run without oil and the engine knocks something fierce. Knock aside, the vast amount of coolant streaming out of the mufflers lets me know a replacement engine is necessary. I do not want to upgrade to an Lt1 or Ls1 I want to keep the l98 due to my budget.
I found a running l98 350 in a 1991 Camaro Z28. Does anyone know if this a suitable replacement for my engine? I don't want any surprises with fitment if possible. I appreciate any input!

Thanks..

ghoastrider1

I would think it should be a drop in.. different tranny tho.

zr1fred

The long block is the same. Water pump, pulleys, fuelrails, valve covers, pan, accessories are different. I'm not sure if the 91 Zs had steel or aluminum heads, if they are steel, the intake won't switch over, though that shouldn't be a problem...use the Camaro one. Your old engine probably died due to being run a long time with blown head gaskets. Real common on the L89.

Bagpype

K. So it's necessary to change the water pump, pulleys, fuel rails, pan and accessories?

zr1fred

yes.

aklim

Mine was steel. IIRC, EGR and intake were somehow different? Not sure anymore

aklim

I would. IIRC the C4 water pump is different from the L98 F-body as is the oil pan. Accessories will be different too or at least the position probably is as is the brackets. Not a big deal

Bagpype

Found the source of the coolant leak. Aaaand the knock..... one head is chewed up and busted along with the piston on that cylinder. The bearing gave way on the crank and the piston just kept slamming into the head till it crumbled apart. Not a head gasket. I'm sticking with the iron Camaro heads I guess.

ghoastrider1

with all the stuff off the front of the engine, ight be a good time to cam it up a bit. Bummer about the old engine.

aklim

Without intake and exhaust mods and a dyno tune, it can't achieve much. The cam would have to be mild enough to be within the window the ECM accepts and still be choked by the intake and exhaust manifold

Bagpype

For future people looking for information regarding the l98 from a Camaro into an L98 c4 Corvette;
The Camaro has steel heads. As stated above, no big deal just use the Camaro intake as the Corvette intake is designed for aluminum heads. I did not use my Corvette heads as one was demolished physically due to the piston pummeling it.
The Camaro intake has different ports for EGR. I just deleted mine as I went with Hedman Headers (more on that later).
The water pump is different. The oil pan is different. The oil pickup tube and screen are different. The dipstick is different. The motor mounts are different. The accessory brackets are different. If you switch all of this over from the corvette engine it should work just fine. I am in the painful of process of getting the "new" engine lined up and shoed in. Not fun.

Regarding the Hedman headers most of us 'Budget minded' peeps use on these engines. I think they are the 68440 ones.
Where do I start? Let's start from the beginning as my saga with them is far from completed. The shipping paint is wonderful. So wonderful in fact that none of my methods attempted got it to come off. I used airline stripper, brush on stripper, metal brush, a 5 hp industrial pressure washer, and many swear words. Paint wins. They were a horrendous pain in the rear to get onto the engine with the accessory brackets where they need to be. Bear in mind, the engine was still out of the car and on its stand at this point. The alternator bolt had to be repositioned, there was some drilling and welding that had to take place. The passenger side header prevented the engine from snugging into place due to clearance so it had to be removed. I did so much research on which headers to buy and these Hedmans got remotely good reviews. Some people had no problems others experienced what I experienced. In the end the old saying "I'm not rich enough to be cheap" applies. I should have spent the extra dough to at least get the ceramic coated headers. But more so ones(from a different manufacturer) that wouldn't have the fitment issues I am having/had.
Besides the terrible headers, this has been a fun learning experience to add to my already deep treasure trove of restoration knowledge. I am having a bit of a hard time getting the engine dowels to go into the tranny due to the engine mounts catching. If anyone has any helpful pointers, I am all ears!