Does anybody know what the length are on 390 intake bolts. I tried finding it when looking up replacements at summit but all have is 3/8 x 16. There's 8 long ones and 2 short ones.
1967-68 FOMOCO 390 428 ENGINE INTAKE MANIFOLD BOLT KIT on eBay! http://cgi.ebay.com/ebaymotors/1967-68-FOMOCO-390-428-ENGINE-INTAKE-MANIFOLD-BOLT-KIT-/110657409342 Several information searches I made show that Ford used spacers on the original engine intake manifold bolts. The spacers go on the bolts in the rear of the manifold. On my build of the 360, two of the bolts had the heads corroded so bad I had to use a reverse spiral flute socket to get em out.
Looks like Ford used all the same length bolts instead of using shorter ones. I'm guessing to make assembly procedures easier if all bolts were the same length. If ya don't use the spacers in the back bolts, they will bottom out in the head and never tighten flush with the manifold. This info came from a Mustang re-builders forum. Some people are sticklers for details when it comes to rebuilding a classic Ford engine. Does the bolts from yours have the cross cuts in the heads of the bolts or are you building from scratch?
I dont have intake bolts. Thats why I asked if I could use 2 shorter bolts that summit has in a kit. But wanna the length to buy local instead of buying that kit. Summit saying that there 3/8 x 16 but doesnt say the length of them.
Mine had the two shorter bolts it being a 1973 build. Honestly I didn't find any info on the actual length of them. I was able to reuse the rear ones on my 360. The spacers are supposed to be 3/4", so minus that from the long bolt length. Set the manifold on the head, use a small metal wire inserted into the hole down thru the manifold into the tap of the head to get the length. You may have to use wood blocks to prop up the head and manifold to accomplish this.
Ok, I measured it. 3in long/depth for 8 of the 10. The other 2 are 2in long/depth with a 1in long spacer. The depth on the is 1in on all 10 holes. Two of the 10 holes on the intake are 1in depth/long and the 8 eight are 2in. Going with 3in grade 8 bolts.
