I just got my Buick 350 back home after a fairly extensive rebuild, and I'm ready to start putting some parts on it. My factory manifolds are in good shape but the bolts are not. I know TA sells a kit but I'm just wondering if there may be a less expensive option? If not, it's no big deal I'll order the TA bolts, but just curious as to what others have done. Thanks!
Replaced all my exhaust manifold bolts with stainless from the farm store (paid about $12). Not show quality (with the correct stamp on the end), but they will outlast the car and I will never have to drill one out again. Still nice and shiny after 4 years of heat and water.
I got a nice set of factory type from ToddGS, with the factory lock washers. They don't have a 350 kit, so I bought a 455 kit and some extra bolts. If you use remflex gaskets (recommend them, btw), they will fit. with no gaskets, TA's bolts weren't long enough. barely any thread engagement. In my case anyway. From what I remember, my '70 driver's manifold needed 1 long bolt, that you need to cut down, 5 mid length, and 1 short, threaded all the way with no shoulder on it. Passenger bolts from the 455 all fit. OR, any old bolts from the store will work. Use lock washers and copper antiseize and you'll be good to go.
Here is a current picture (kind of hard to get under everything to get a good pic). Seems like there were 4-5 different size bolts, so I took what was left of the old ones in and bought matching lengths of stainless. Also, read the torque specs before tightening, they are really low on the exhaust manifold. Too tight and they'll crack the manifold... I had to replace both manifolds when I rebuilt the engine because someone had overtightened the bolts in the past and cracked both of them.
I like stainless too. You might think ex manifold bolts are special but they are not. They tend to be about a grade 5 which is just as common as you can get. Oddly enough, stronger bolts like grade 8 don't do well here. Hardware store stainless is also about a grade 5 but are more durable and stand up to heat cycling much better. Jim
That's more or less what I'm really wondering. A lot of people will say "don't buy car parts at the hardware store" but in some cases, aren't bolts just bolts? I was sorta wondering if that ram-lok head really mattered for anything other than appearance.
You usually need to look at the grade. For a lot of stuff, grade doesn't matter. For important stuff (suspension/brake/steering components), you need a high grade. I usually buy bulk grade 8 bolts in all sizes and use those for most stuff. Look at the marks on the head. Here is a chart. https://www.boltdepot.com/fastener-information/materials-and-grades/bolt-grade-chart.aspx
The I-H guys have spent a lot of time on this issue, because with their SV series engines this is a common problem. For whatever reason, using grade 8 bolts here leads to bigger problems involving bolts corroded in half, stuck, and sheared off, and continued exhaust leaks while the softer grade 5 bolts usually come right out. But they still corrode. It seems like maybe the expansion coeficient of the cast iron may be closer to the grade 5 than the grade 8 but that's just a guess. In any case the stainless is still better because it is less likely to corrode and stick. Use a good anti-sieze. A number of those guys resorted to various methods to spring load the manifold bolts but the springs had to be insulated from the heat somehow. It ended up getting a bit complex. Bottom line though, you have to match the fastener to the application. Sometimes hardware store bolts are the right answer, sometimes they are not. Jim
I worked on an engine one time that had exhaust manifold bolts spaced away from the manifold proper by sleeves about an inch long. All of the bolts came out like butter, hardly any effort. No, I don't remember what that was. Maybe a Ford? It did seem that isolating the bolt from the major heat source ( the exhaust port ) helped greatly to reduce corrosion.
http://www.v8buick.com/index.php?threads/free-shipping-for-1-week-on-master-bolt-kits.347181/ Todd can sell you bolts
