327 sbc swap

[blackngold1982@yah]

i have a 1986 gmc k15 with a 305 in it i want to put a 68 327 in it.there is no dipstick with the 327 can i use the one off of the 305 if i use the 305's oil pan and can i use the 305 heads on the 327???? i read come where that you cant put oil in the heads of the older motors is this true?

[toddman67]

Chances are that the 305 pan is not going to fit the older 327 engine. If the pan is shot get an aftermarket pan and an aftermarket dip stick and tube. As far as the heads are concerned, I would stick with the 327 heads.

[J-Ri]

That sounds like way too much work just to gain 22 cubic inches. You'll most likely run into issues with things not lining up. Engine mounts, exhaust, maybe transmission. I don't know that for sure, but that's a big age gap to assume that anything will be interchangeable. If you end up swapping them, and don't want to spend weeks fabricating stuff, make sure you measure everything twice. Also, if you have emissions testing in your area, you can't swap in an older engine or you'll almost certainly fail. I know next to nothing about the requirements, but I have read that many times, I have also heard that after "X" years you don't need to take the tests. Check into that if it's an issue there.

[toddman67]

I assume that the reason for the change was due to the 305 being shot. As long as he re-installs a manifold with EGR and runs a cat. He should be all set. I believe this 23 year old truck only had electronic spark control by use of a knock sensor and the egr and cat for emissions.
Always good advice to check with local emissions laws as mentioned.

[toddman67]

Disregard my last post, I was thinking that it was an 82 truck. 86 used O2 sensor. Air injection manifolds, smog pump and divertor valve and purge canister.
Sorry for the wrong info on previous post.

[1968 Pontiac]

No problem to throw that old 327 in there. Everything, and I mean everything except any brackets that may bolt to the heads, will bolt to the 327. If the 327 has the original 68 heads it will have short water pump brackets which means that none of the accessories bolted to the heads (i.e. there are no holes drilled and tapped in the heads to put later style accessories on these heads). It'll be up to you to make sure you meet emission requirements. I have a car with a factory original 275hp 327 (right down to the ground straps from the valve covers going to the firewall). Believe me if your engine is good, and is at least the 275hp version, your truck will come alive. It's not about the 22 cubic inches if you've never driven one of these old 327's. Due to a previous owner stripping the fuel inlet nut in the original 4bbl rochester (I've since found a correct original carb again) I had to switch mine over to an edelbrock performer intake with 600cfm Holley carb. Before the change the engine started to loose power over 3000rpm, but now she's got good power right to 4000rpm+. No problem smoking most of the newer cars ... and that's in my almost 4000 pound 68 Pontiac (see my avatar to the left) with optional TH400 tranny and standard rear end gears. Must be the optional factory four link suspension that gives me the advantage ;-)