V6 to v8

[Joe Dirte]

Ok my 98 is givin me fits and a quick trans job is slowly turnin into a full-on nightmare. I got other things i wanted to do down the road on it but with all im gonna be cuttin n breakin to do job i got a couple questions. Sorry if i jump around, its a bad habit.

1. I may just pull motor n trans together since i got new front sheetmetal to put on and had other things planned for truck. What all will i need from the 98 305 to make it work in my 96 with a 4.3? My 98 harness n pcm or just find a 96 pcm n harness for a v8 single cat truck?

2. Exhaust. Bolts are breakin and roundin off nuts. Gotta love ohio. I wanted to do some headers and dual cat pipe and build myself a true dual system. While im at it if i do yank 305 n trans, if i wanna go up to a 350 and to go dual cats will i just need harness from a dual cat truck? Should i get pcm too?

3. 4.3 truck. Nv3500 parts (flywheel, clutch etc) will work on the 305? If i do the swap ill probly get all new clutch pieces while im in there.

Both trucks will get noses pulled for swaps (one at a time so i still have a driver), new/used panels, frames cleaned n painted. I wanted to do a lower mile 350 in my truck anyways and wouldnt make since to me with all trouble im havin now to unbolt it all again later when i can pull thr whole thing as one n stab the new in. Ok i think i made it all clear as mud. Thanks for any advice.

O and tailpipes. Goin chrome slant cut but cant decide if i want straight out either side of hitch or angled toward bumper corners. Probly wont make any difference right?

 

[df2x4]

A note about the PCMs, the '96 and the '98 have a different number of connectors and therefore different wiring. I think it would be much easier to leave the '96 PCM in the truck and get it tuned for the 305.

Honestly though, I don't think I'd spend all that time, money and effort for that swap. The improvement isn't going to be enough to justify it IMO.

 

[c1500deathtrap]

I wouldn't go through all of that trouble to end up having a 305 in my truck. Especially when 350 vortecs are a dime a dozen.

 

[c1500deathtrap]

But all you should need to do is get the pcm reflashed and change out the injector portion of the wiring harness. Flywheel and clutch should be ok, unless theres some kind of weird balance thing going on there. Motor mount are different on the v6 truck, but the mounts from the v8 truck will bolt onto the frame. You're really hard to follow here bud. But I hope i helped.

 

[Joe Dirte]

But all you should need to do is get the pcm reflashed and change out the injector portion of the wiring harness. Flywheel and clutch should be ok, unless theres some kind of weird balance thing going on there. Motor mount are different on the v6 truck, but the mounts from the v8 truck will bolt onto the frame. You're really hard to follow here bud. But I hope i helped.

Ur right on the 4.3 to 305 n might as well go with a 350. Ginna stop by yard tmrw n see what kinda price i can get on a couple low mile 350s. Yeah my mind bounces around on ideas like crazy n i even get lost sometimes, workin on a vehicle n spme brilliant new idea pops up n i drop what im doin to figure it out.

 

[c1500deathtrap]

http://harrishighperformance.com/?page_id=27 I don't much like this guy anymore, but the page outlines what you need to do for your swap.

 

[ima93chevyguy]

Yea if you're already having trouble now don't give yourself more headache by swapping in a 305. Go straight for a 350.

 

[L31MaxExpress]

Food for thought if you have a low mileage 305 that runs good just use it. No telling if that junkyard 350 has been cared for at all. You could get it in the truck and it could be a rod knocker or have cracked heads.

A 395' marine cammed 305 makes more horsepower than a stock 350 does. The 395' cam can be had for under $200 new and works with the stock springs, lifters and valvetrain. With long tube headers, a decent exhaust and the 395' cam a L30 305 makes in the 260-280 hp range. The cammed L30 in my Tahoe had no problem moving around the truck and got great highway mileage.

 

[Joe Dirte]

Food for thought if you have a low mileage 305 that runs good just use it. No telling if that junkyard 350 has been cared for at all. You could get it in the truck and it could be a rod knocker or have cracked heads.

A 395' marine cammed 305 makes more horsepower than a stock 350 does. The 395' cam can be had for under $200 new and works with the stock springs, lifters and valvetrain. With long tube headers, a decent exhaust and the 395' cam a L30 305 makes in the 260-280 hp range. The cammed L30 in my Tahoe had no problem moving around the truck and got great highway mileage.

Mine are vortecs but would that cam be ok for a 350? My 305 as far as i know has over 230k and my local yard sells me good low mile motors. Lets me check em out n drive trucks before they yank em.

 

[L31MaxExpress]

Mine are vortecs but would that cam be ok for a 350? My 305 as far as i know has over 230k and my local yard sells me good low mile motors. Lets me check em out n drive trucks before they yank em.

By my way of logic the youngest 350s in a truck were built in 2002. Even at 10K a year, they will have 150+ on them. Might get lucky and find one from a low mileage wrecked van that was used for roadtrips.

That cam was factory in 305 Marine engines. Factory rated at 260 hp and 308 tq. Was also used in the 350 marine engines. 300 hp and 370 tq.