Hello Everyone Can I ask for some advice here. I have a 430 engine in a 1968 Wildcat and it needed to be reconditioned. It turns out that both cylinder heads are cracked. The machine shop offered two 455 heads and said that they will fit onto the original engine and I can also use the original 430 intake manifold. The issue which I am faced with is that the 455 heads have 2 EGR ports front and rear. Is it possible to tap and plug the four holes, or should I find a 455 intake manifold? Your advice would be appreciated. Thank you John
Yes. You can plug off those ports. Some heads have a few other differences with passages. You will need to have the upper oiling passage mod, (unless you change the pushrods/lifters/cam changed over). And compression will be much lower. Others will add knowledge to this. What all work are you planning on having done to the 430? That will help with providing relevant information to your project.
Not all 455 heads work the same, get a casting number and find out what year heads they are.......they all will bolt down, but the will take some plugging of ports. If 73 or later you will need to plug a water port in the deck surface. Not really needed to tap any of the hole.....freeze style cup plugs will work if you can get the correct size. As stated if using 430 factory rockers, newer lifters with the correct push rods will be required to used the 430/400 shafts still
Hello Michael and Ben Thank you for taking the time to answer my message it is appreciated. Wow, getting to know the 455 is quite a learning experience and I never realized that there was so much difference between the 430 and 455. My story goes like this, a year ago I decided to give my Wildcat a tidy up including tuning the engine and changing the intake manifold gasket. It was running OK, however it was using coolant and was sluggish. When I removed the intake manifold I could see that the camshaft lobes were worn mostly on the left bank, (1.3,5 and 7 cylinders). I also had three or four noisy lifters which used to eventually quieten down. Vehicle has done 104000 miles, so time to replace the camshaft and lifters. The timing chain were also worn and once I removed the camshaft the project continued to develop, as the front cam bearing was badly worn. I wanted to clean up the manifolds and when taking them off, I found that the bolts had wasted away and there was little holding them onto the heads. At this stage I thought that I should remove the heads and have a look at the top of the cylinders and bores. All seemed Ok with no signs of oil on the top of the pistons or ring wear. However number 8 cylinder was scored and at that point I decided to remove the engine and take it to my local engine reconditioning shop. They magna fluxed the heads and found them both to be cracked on the outside around the valve guides. The guys at the machine shop could not find any 430 heads, however they had a pair of 455 heads, which they said would be Ok. It is hard to believe that this engine was running Ok before I stripped it down, (this is a good testament for Buicks). Therefore I had the shop recondition the block, (re-bore, new pistons, crank ground, and I had them balance the crank and rods, provide me with a new flex-plate, (old one was not running true). I up graded the oil pump and replaced the pick up tube with a larger diameter one and did the modifications as suggested on this site. All the block, deck and head surfaces were machined to clean them up make sure they were straight. Other parts included, new camshaft, camshaft bearings, lifters, timing chain and gears. The harmonic balancer was cracked and I replaced that. A few years before and when I brought the car I had replaced the badly worn rocker shafts on both banks, so they still looked new. The heads were stripped and exhaust valves replaced, new valve guides fitted, along with new seat inserts. This happened a year ago and the vehicle sat over a cold winter in my un -heated garage, while I did other work on the inside of the car and I also removed the transmission while the engine was out and reconditioned that. I did the transmission work myself and had a friend, who owns a transmission shop), dyno test it for me, before putting it back in the car. Therefore I now have to make a decision about what to do next. The plugging of the holes is not a big problem, however I am concerned about where and what is connected to the EGR ports and the other modifications which you have both suggested that need to be done to get the engine running well. I will have a look for the casting numbers, as you suggested and see what year the heads are. Thank you once again for your comments. John
Your lifters are they for the 400/430 or 455. This must be found out. The 400/430 oiled the rockers through the head to the shafts, the 455 ois up the hollow pushrods to the rockers.....if usin 455 lifters with the 400/430 rockers you need to hollow pushrods with the correct size ball on the end....the earlier pushrods used bigger balls. If unknown post pics of your parts
Hello Ben Thank you for your message. The push rods are solid with no centre hole through them and the rockers are lubricated through the heads. I am sure that the parts which came with the 430 recondition would be for a stock standard 430 engine, including the camshaft, lifters etc. I used the older push rods and rockers, as I had replaced them a few years ago and they looked good. I think my easiest solution would be to find a pair of 430 heads and change out the 455 heads. My Wildcat is a cruiser and not anything faster than that. I would love sometime in the future to get into fitting a modified 455 into a '69 Riviera which I have sitting around as a parts car. Therefore your advice and comments are greatly appreciated. Do you know where I could find a good set of second hand 430 heads which need to be reconditioned? Thank you once again. John
Since the heads are at the machine shop, they may be able to drill the 455 heads to oil through the rockers. It is just a passageway that mates up the holes in the block deck. Compare your 430 heads to the 455 heads and you will see the difference. The holes in the block are at the forward side of the deck surface on each side. There are matching holes in each 430 head.
What I would recommend is to put a wanted aid here and see if anybody has a good set of 70,71,72 heads,70 and 71 preferred,then,as Larry said,have the machine shop drill 4 holed on these heads and use everything also that you have.Better yet,get yourself a set of Edelbrock heads or TA S-1.Bruno.
Most ppl will agree if your 430 rockers have good shafts, not worn, and the tip are not worn where they contact the valve tips, the older rockers are better and stronger, especially if adding some extra lift. Might want to check prices.....drilling the hole might cost as much as 455 lifters and hybrid pushrods. But 1 or the other will need done. The earlier 400/430 heads were more prone to cracking, also depending who does the work they need to be careful. I have a really nice clean set of large port 430 heads that had a few exhaust replaced.....and the shop didn't do the work well snd the seats fell out within 250 miles if run time. Having a stk set of heads redone should be figured into this equation too and try to figure what is most bang for buck. Some shop's are getting 750 plus to redo basic stk heads Bolting the 455 heads to the 400/430 block won't require that oil hole in the block to be be plugged, the 455 head will block that right at the head gasket. Just require the hole in the head to be drilled or the lifters and pushrod changed. The 70/71/ early 72 heads will take less plugging of smog ports, anything later than 73 will as stated require a coolant passage plugged as well
I have a bare set of 1967 430 iron tall port heads. (1967 Electra about 50k) They have been MPI and no cracks. $500 plus actual shipping from Florida Panhandle. (I have all the valve train parts) I can use Fastenal or other preferred method to ship. I have no idea what it would cost, to ship. Or if anyone is traveling that way and wants to transport them for a fee.
Hello Everyone Thank you once again for your messages and for the "education", its great to read your comments and I am learning fast the differences between the two engines. The 455 heads I have are from a 1975/76 Buick, (would they have come off either an Electra or Riviera of that era?). The casting numbers are 1246322. I am suprised that there was an EGR system on these engines in that era. I have a few 1983 Rivieras and they have a lot of emission stuff on them. Therefore with the existing 455 heads I would have to do the oil modification and block off a coolant passage. I am leaning towards finding a good set of 430 heads which can be reconditioned. I am surprised about your comments that these heads are prone to cracking and that coupled with their lubrication issues, are these engines really that good? I take it from your comments the earlier 455s, 1970/1971 are the ones to have? Thank you all once again for taking the time to comment it is appreciated and I certainly have something to think about. I would love to have a Buick with a "worked" 455 engine in it and will keep dreaming about it. There seems so much which you can do with the 455 engine to get it to perform. Regards John
The earlier 455 heads would just take less plugging of holes to make work, but all could be make to work one way or another, just carefully weigh out all the cost involved
Also keep in mind all 455 heads have a slightly larger intake manifold bolt size and the exhaust crossover port is different on the later 455's
Hey John Sorry to hear about your Cat problems. My friend Bill has a real nice set of 430 heads that were magnifluxed, valve job done, all ready to go if you’re interested. We are on our way to the Buick nationals in Denver right now but I saw your post and thought I would throw that out there. Feel free to call me if you want. Rob Holmes
Hello Everyone I would like to sincerely thank everyone who commented on my post. The final outcome was that I was able to buy a pair of 1968 430 heads through Wildcat 4's friend Bill and now have them fitted to the car and its running again. The replacement heads had been reconditioned and looked in great shape/condition. I now have a pair of 75/76 455 reconditioned heads sitting on my shop floor and if anyone is interested in them, please get back to me? Thank you once again. John
