what do i do to make a 408. get a 6.0L block, buy a 4" stroke crank, 6.125" connecting rods, pistons for a gen III sb with 4" stroke, 4.030" bore, and 6.125" rods, bearings, and piston rings. have the block bored to 4.030" bore. this roughly will give you the parts for a 408 short block. (note, same actual length as a long block). assemble short block with these parts. as for camshafts, you want to buy one for a gen III small block (chevy) and preferrably with an expected valve lift at around .500" to .800", duration of around 210º to around 270º @ .050 lift. nobody that i've seen so far has a cam that is for a 408" engine specificly and to cover all applications for a 408" engine. cylinder heads are tough, you can use stock or some aftermarket heads. stock heads should be cheaper. aftermarket heads are more expensive. it is often thought that the more you spend, the more power you will make...

 

Guys I cleaned this up, please keep the personal shots to PMs and let the thread take its course. I think the question asked was valid, if you do not have anything to add in this thread that pertains to the question asked please move on. If there is a problem with this, feel free to PM XLR8NSS or Greggo.

 

Much more off-the-shelf piston choices can be found using the 6.125 gen1 sbc rod. You can run an LQ9/LQ4,5.3 rod and save some money. You may have to go with a custom made pistons though to get what you want. The whole deal about the 4.100 stroke not clearing is just common place to most seasoned engine builders, I would even expect it to not clear with a 4.00 stroke. For the savings of $2K i'd go with an Eagle rotating assembly over Lunati or Callis. The later kits come balanced and clearanced from what I understand (somebody verify that). Eagle makes quality products and are an extreme value.

 

That is as straight forward as you can put it. That is "how to make a 408"

 

I have the 4" Eagle Crank and 6.125 rods and the machine shop checked it and didn't find anything wrong with it. The only thing the engine builder found was that the cam was a little close to one of the rods so he removed some material so it would for sure clear. and for some one asked how much was the machine work. it was like $350 for cleaning, boring, honing, checking balances, and assembly. I paid him $400 because he worked half the nite getting it done for me so i could have it for the weekend. Some people think its crazy to have the machine shop to build the short block but i say its worth every penny.

 

i got a phone call about this thread today. i see that it was cleaned up quite a bit.

i won't get into who did what or why. but my recommendation to all is, If you see a thread that has a question that has been asked a dozen times, and you feel you need to point out use the search button, then how bout you use the back button. I don't want this to turn into sites like thirdgen.org where you can't post a damn question because they have sticky's saying not too cause it has been asked a thousand times.

i'll give you an example. hot rod magazine has built the 350 engine a million ways. but they keep making articles on building the same motor. WHY? because things change, new people might not know what their past readers know. It is a popular engine and will continue to be so. same thing goes here, if someone post a question on a topic and that person is new, lets not be brash and basically kill this guys desire to learn because he is afraid to post questions. Everyone can learn something from repeat questions. I do. we all had to start somewhere.