I want to stroke my 91 S10 2.8

[streetmaster]

The 2.8 TBI in my 91 ext-cab S10 has over 250K on it, and its long over due for a rebuild. Dont know much about thiese small motors, but would like to get some more power than stock.

The truck came with a 5speed tranny, and would like to retain if possible. Plus i plan on keeping the truck as a TBI aswell.

It is my understanding that a 3.4 crank and rods can be used but not sure about the pistons though. Please Advise

[robertisaar]

using a 3.4 crank in a 2.8 would essentially be making a 3.1...

the smarter and probably cheaper move would be to grab a 3.4 from a camaro and swap all of your necessary intake hardware onto it...

and if you use the injectors from a 4.3TBI, it flows the right amount to where if thats the only modifications, a chip isn't necessary, but suggested

also a 4.3 throttle body would help.

[streetmaster]

using a 3.4 crank in a 2.8 would essentially be making a 3.1...

the smarter and probably cheaper move would be to grab a 3.4 from a camaro and swap all of your necessary intake hardware onto it...

and if you use the injectors from a 4.3TBI, it flows the right amount to where if thats the only modifications, a chip isn't necessary, but suggested

also a 4.3 throttle body would help.

How much more power does the 3.4 have over the 2.8?

[bszopi]

A TBI 2.8L makes ~125hp. The 3.4L found in the 93-95 Camaros makes ~160hp. So you are looking at around a 25%+ increase in power. Use the 2.8L accessories and intake, and you will make less, but I bet it will still be upwards of 150hp, or around a 20% increase in power.

http://60degreev6.com/content/60%C2%BAV6_Family_Tree

[streetmaster]

A TBI 2.8L makes ~125hp. The 3.4L found in the 93-95 Camaros makes ~160hp. So you are looking at around a 25%+ increase in power. Use the 2.8L accessories and intake, and you will make less, but I bet it will still be upwards of 150hp, or around a 20% increase in power.

http://60degreev6.com/content/60%C2%BAV6_Family_Tree

Not sure if the 2.8 in my 91 S10 is internally or externally ballanced, but the 5 speed should work aswell right?

[robertisaar]

i think the 5 speed from the f-bodies is slightly different, but if you want to use the 5 speed you have already, yes it will work...

[bszopi]

All 60V6s after 1987 are internally balanced.

[geoffinbc]

With a good cam and the intake bored for a 4.3L TBI you will have a bit more than 150HP. A few years ago moneyclip on S-Series.org got 187RWHP with a 3.4L with a 4.3L or Holley TBI (can't remember which one) and headers. I believe the cam was the stock Camaro cam as well with stock rockers.

In any case you will make more than the Camaro engine did with a couple mods and a little work. I firmly believe gasket matching goes a long way on the iron head engines so I would suggest you do that when you tear the engine down.

If your set on rebuilding your current block than a 3.2L can be made from a 2.8L with a .040 overbore 3.1L crank and pistons. If you a good junkyard scrounge you can get the crank cheap but the pistons will have to be new. You can use your rods. A machine shop will have to balance the assembly so I suggest you contact a shop and get an estimate on the following

-Decking the block
-Rebuilding the heads including guides, seats and surfacing
-Cutting the crank for cleanup if necessary
-Dynamic balancing the rotating assembly
-Hot tanking the block and heads

Once you get a price I would then weight that against the cost of the crate engine. You will most likely find, like I did, that the crate is about the same price. However the crate will not allow you to clean up the block casting, gasket match the heads and intake or choose your cam and valvetrain without taking it all apart, buying new gaskets and throwing away perfectly good new parts.

So just think about it LOL
http://members.shaw.ca/betterthanyou/isuzueng.htm this is the engine I built and I kept an accurate budget you may be interested in. Everything is in CDN dollars.