will a 305 and a 350 bolt up

[nicholas4568]

someone told me that my trans will bolt right up to a 350 and all i have to do is change the motor out, will a 305 and a 350 bolt up, and has anyone stuck with the 4.3? i ordered the book but have to wait to see but if anyone can help, and also, i have a 91 s10 2wd how do you find out the trans? today i started it up and the guages went crazy my oil pressure and water guage went all the way to the top but the car seemed to run fine? anyone that can help

[Melonhead]

Nick, if your 91 came with a 4.3 the trans will work with a SBC. The reason a 4.3 trans will work, is the 4.3 and a SBC are 90 degree motors. The bellhousing and mounting points for the trans are the same. The 2.8 v6 is a 60 degree motor and is a smaller bellhousing than the SBC and 4.3 v6. both the 305 and 350 will bolt to the 4.3 trans, because the trans bolt pattern is the same.

[stevo67]

As Melonhead said, the 4.3l V-6 and a first generation (55-86ish?) Small Block V-8 have the same bellhousing shape and bolt pattern. Infact, GM designed the 4.3L V-6 around the 350 V-8 (bore, stroke, rods, pistons, timing sets, etc.).

If you've never done an engine swap with components that were never available as a factory stock or factory option, I would highly recommend you wait till you get the book before tearing into your truck. It is not as simple as pulling the V-6 and dropping in a V-8, but if you have basic mechanical ability, it's not extremely difficult.

I would also recommend that you get your truck operating 100% tip-top shape (gauges, wiring, etc.) BEFORE doing the swap, as you will most likely chose to use the factory gauges (by putting the 4.3 v6's sending units <water temp., oil pressure, etc.>into the V8), sensors and relays.