Hi, I wanted to try to get a good answer from a GM/Chevy member on an engine swap. I have a friend who is planning on buying a 1984 Chevy S10 4x4 shortbed. It has the 2.8 liter V6 engine with 4-speed manual transmission. The truck is in alright shape for an 84, but the engine has spun a bearing. My question is will a 4.3 liter V6 from that era be a drop in conversion? Or in other words will the engine bolt right to the frame as if you were dropping in another 2.8? Also, will the 4-speed manual transmission bolt right up to the 4.3? I know the 2.8 V6 has a cast aluminum cylinder head, while the 4.3 V6 has a cast iron cylinder head and makes for a tougher, more reliable engine. I appreciate any reply and thanks.

Unfortunatly, no. Everything is different, the bellhousing, frame mounts, etc. The 2.8 uses whats known as a 60 bolt patern, you'd need the tranny, frame mounts and engine mounts. Also the iron versus aluminum controversy has been raging for years, but in this case, yes the 4.3 is better.

Thanks for your info. That being said, will getting frame mounts and engine mounts then allow for a 4.3 to drop in on the 1984 S10 frame? There can't be much difference between an 84 and 88 frame. If there is I wouldn't know the difference and how much of a job it would be dropping in a 4.3. What bolt pattern does the 4.3 use? I am not 100% sure but I believe GM started using the 4.3 V6 for the S10/S10 Blazer in 1988. Correct me if I may be wrong. Thanks.

However, the 3.4 is a near bolt-up replacement for the 2.8. A number of us on the Isuzu side have replaced our 2.8's with the 3.4. It may even be easier on an S-10, depending on a couple of details, such as which side the starter is located on.

Jim, what GM vehicles used the 3.4 V6 and what was the first year for production on the 3.4 V6? Also, did the 3.4 V6 come in any GM 4WD vehicles? If the 3.4 V6 was an engine strickly used in FWD/RWD applications wouldn't that engine need a 4WD oil pan to clear the front axle? I would think you could put the 2.8 V6 oil pan on the 3.4 V6 and be OK. Would you also know the horsepower/torque ratings for the 3.4 V6? And finally the most important question, does the 3.4 V6 have a cast aluminum or cast iron cylinder head? Thanks for your info and I do recall other members swapping the 3.4 in for the 2.8 at the Isuzu board. The Isuzu board is where I spend most of my time anyways. Appreciate your reply.

The 3.4 came in Camaros.

The 2.8 oil pan, water pump, etc., are used. The 3.4's that we are using are the iron head versions. I think that there are some issues with using the aluminum head versions. Ed MC on the Isuzu boards has all the details on the swaps.

Essentially, what all of us are doing is using the 2.8 intake manifold, bored out to 4.3 diameter and running either a 4.3 TBI or a Holley on top of that.

The GM Performance 3.4 with a carb is rated at 160 HP.

I think that I was the first to do this swap, but others have done a cleaner version since and Ed has all the documentation and is a wealth of knowledge on the topic.