Engine and Tranny Swap...Questions

[HARF_86CHEV_1/2TON]

I have a 1986 chevy 1/2ton short box with a 4.3L V6 that is married to a manual 3 speed tranny... (3 on the tree)

I want to swap the 4.3L v6 with a 5.0L V8 that I have in an 84 Chevy Impalla that I recently picked up.

My Question is wether or not the fly wheel and bellhousing from my 4.3L 262 V.6 will bolt directly to the 5.0L 305 V8?... The 305 is connected to a 3 speed automatic tranny in the impala.

I would also like to know if I will have to modify or move the engine mounting brackets on the 305 from the impala to make it bolt into the 1/2 ton.

Anyway any suggestions or answers would be greatly appreciated.
I just want to know what i am dealling with before I take my truck off the road to make this swap.

Thanks

P.S. Go flames go!... As a hockey fan i could not resist haha

[MagicRat]

This swap will not work with the 3 spd manual transmission. The 305 will not have a pilot bushing hole drilled into the rear of the crankshaft.
You need this hole and bronze insert bushing so the clutch will work properly.
A machine shop is required to drill the hole as it must be precisely on center.
Either swap the auto trans along with the engine, or remove the crankshaft from the 305 and send it to a shop for the bushing hole to be drilled.
That being said, is it worth the trouble? The '84 305 is a bit of a dog, stock ( I have one) and for all the trouble why not sell the 305 with the trans and locate a 350?

[HARF_86CHEV_1/2TON]

Well that is kind of a bummer...

Would you happen to know if the automatic tranny would mount into the truck if i decided use it with the 305??

What are some good things to do to my 305 to make it less of a dog...
Just wondering because i was thinking of putting some money into it as far as performance wise anyway.

[MagicRat]

There were many thousands of those trucks sold with a 305 and an auto. See if you can find a wrecking yard truck and swipe the transmission cross member, shift linkage and engine mounts. An automatic shift steering column would help. As for performance, to start, make sure you have at least a factory 4 bbl carb and intake manifold, and that everything is tuned and adjusted properly. (A performance aluminum intake is even better) A swap is a good time to install headers and a dual exhaust. If you want more power, its time to look for a camshaft and better cylinder heads, and for that effort you may as well swap in a 350.

[HARF_86CHEV_1/2TON]

I actualy have a parts truck that has is a 1986 1/2 ton and it has a 305 with a 3 speed auto tranny with overdrive.
I guess that that tranny should bolt right up to the engine from the impala would it not?
Basicly the only reason i am using the engine from the car is because it runs perfectly.

I agree a 350 would be a better engine to swap in... but I have these 305s at my disposal right now and the fact that college eats up alot of my cash is about the only thing stopping me right now (gas too i guess). But some day i plan to swap a 350 or 454 into it. I plan to keep this truck forever probly anyway.

[curtis73]

The 4.3 is a 350 with two cylinders taken off. The bellhousing bolt patterns are the same. The flywheels and corresponding torque converters are the same (as far as bolt patterns and fitment are concerned). I'm pretty sure that the added length when swapping from the 6 to the 8 is in the front, so motor mounts and tranny mounts should be identical... someone will correct me if I'm wrong.

I agree, though. By the time you've made a 305 perform, you could have bought a 350. Its not just displacement, the 305s big issue is its small bore. It shrouds valves and often thwarts best attempts at breathing. Put it this way; a 305 is basically 87% of a 350, but its streetable power potential is not 87% because of the bore/stroke ratio and shrouding.

[HARF_86CHEV_1/2TON]

Thats good to hear about the bell housing bolt pattern all being the same. I am probly going to finish pulling the engine out of the impala this weekend so it is good to know that that will not be an issue.

I TOTALY here you guys when you tell me to go get a 350 believe me i would.
I am most likley going to buy a 350 crate engine when i get enfough extra money built up.

But for now I regret to say that i am most likley going to drop in the 305 and use it till i get all my lowering and paint work done. I know its not the best engine to use but hey... it runs mint.

Thanks for all the help and let me know if anyone has any other advise.