Two weeks ago I found a 68 225 for sale and listed it under the "sales leads" section of the forum. Zero interest! That got me to wondering, is the 430 not worth the effort it would take to put it in a 66 Skylark, and should I still keep hunting the elusive 455 engine? What are the pros and cons of the two engines, can a 430 be punched out to a 455, are cams and such available? I didn't have the time or means to grab the 430, but thought it would surely make my Skylark fly, considering it only has a 300 in it now. What do you think??
I don't have much experience with these engines but I do remember my dad having a `69 Electra with a 430 when I was in high school and I was really impressed with how fast that car was. When he got the new `72 Electra with a 455 I remember thinking that that car couldn't hold a candle to the 430 car. I'm sure others will pipe in here because there are oiling issues with the 430 that were later corrected for the most part on the 455, but honestly, evenin stock form I that 430 would be a huge power improvement over the 300.
400, 430,455 are the same engine with diff bores. Same cam, heads, crank, etc. Most of the time a 430 cannot be bored to 455, but with the perfect block it can be done. 430 is a great motor
In my first 66 Skylark I had an engine tranny combo consisting of a 430 and a 4 speed. :3gears: Need I say more? Scott
It is a great motor and very underrated, IMWO. 430 heads came with regular or tall "big" ports, depending on year/model/option. Rocker ratio 1.59 on 430 vs 1.55. Also, rocker arm shaft oiling on 430 vs through-the-push-rod oiling on 455, different pushrod dimensions (I run adjustables), different exhaust manifolds, and yes, you can bore a 430 out to 455, but that's a technical decision based on your desired combo. Yardley's site is a good place to start looking on 430 mods / idiosyncrasies. The thing to do would be to find out the 430's head casting numbers and check to see if they're the big-port variety, which you can look up RIGHT HERE. Those are worth money, although you'll absolutely, positively have to get them magnafluxed as the 430 heads had a tendency to crack in certain areas - repairable in some cases (Greg Gessler fixed one of mine) but this is pretty much a must-do. :Smarty:
This is interesting to me. I have heard/read previously about a limited number of "big port heads" making their way onto 430 motors for model year '68. The jist of it was that an early build '68 would be the most likely candidate over one assembled later in the model year. I'm going to ask a naive question - are the casting numbers visible with the motor in the car? or does the motor need to be out of the car or disassembled to see these? Thru body tag and serial number decoding I know my Riv was assembled somewhere in September/October of '67, and has it's original engine. Now I'm curious to know if it has the big port heads.
Head casting numbers are under the valve covers; viewable with the engine in the car, but you have to do some disassembly (valve covers, A/C compressor, etc) to get a look at them.
One other thing, I believe all 430's had 10.25:1 (10.5?) compression stock. A lot of 455's had 8.5 or 8.0. Something to think about if you just want to bolt one in and go.
late 68 and all 69 430 blocks had 455 water jacket inserts. Most can be bored to 455 if core shift allows. I prefer late 430s and bore .062 over to the standard chevy 4.250 size.
If you are in Florida and in the Daytona Beach / Ormond area, at exit 273 off I-95 ( Rt 1 ) if you go off that exit and go north on 1, keep your eyes peeled to the left, the second junk yard you will come to has a black two door full size Buick sitting right there next to the road. It has vent windows so it can be newer than 69.. It has been sitting there close to a year. It looks like it has a engine in it. I always say I'm going to stop but there is no where to park with my truck.. If I ever go that way with my car I'm going to stop..
Bore the suction side of the block to 5/8" and convert it to 455 oiling, blah blah blah. Biggern' a 427 Ford or Chevy, ain't it??!!
