300 2bbl to 350 4 bbl swap

**JAMES OWENS** · 11-18-2010, 05:37 AM

1967 buick skylark hrdtp
I am swapping my original v8 300 2bbl ( no a/c ) with a auto st3oo transmission for a 1970 buick 350- 4 bbl ( no a/c ) with a th350 auto trans. The questions I have are " What problems can expect". Like --
will i have to change engine / transmission mounts. Will I have to get a
bigger radiator. Hood clearence issues. Exhaust/header clearence issues.
Is there a book/video/link that addresses these questions.
Thanks JIM

**Ted Nagel** · 11-18-2010, 01:01 PM

James, good swap and IMHO pretty easy. The th350 will use the same mounting and driveshaft. I think on my 65 I used the engine mounts from the 65 and they bolted right on the 350; then the engine just dropped right in. I used the ps pump from the 300 and pulleys from the 300...did not even take the wires off the alternator, just left that and the ps pump in the car and it all bolted up pretty well. No exhaust manifold problems.
Let us know how it goes!

**JAMES OWENS** · 11-19-2010, 04:59 AM

Thanks Ted----- I am wrong to think I need the original size radiator that came with the V8 350 4bbl ( no a/c )---Or will the V8 300 ( no a/c )radiator be sufficent enough flow. If budget allows it ---I am going to buy a new 3 or 4 row radiator, but right now I want to concentrate on the engine/trans & rearend-- can always swap out a rad. at a later date.
Also --Did you have any -" Air cleaner to Hood" issuses
Thanks for all your help -----JIM OWENS

**Ted Nagel** · 11-19-2010, 02:37 PM

Well, I'm all for trying the original to see...

I've got a Wildcat or 2 with the original radiator and they are PUNY compared to the recores I have had done. My 350 has had a little work done and the original HD/non a/c radiator is struggling on hot days.

A good radiator shop can use your tanks and put a better core in there. I've had good luck with what they call the 'D' core... closer tube spacing, more fins, better cooling.