I'm building a 300... 5/19/12 SHE'S ALIVE!!!

[max03]

Great build thread! I recently purchased a 68 swb with a 300 and three on the tree, engine had a bad headgasket so I pulled it yesterday, hopefully I can finish disassembly tomarrow and send it to the machine shop. This will be my first build and your post have offered great info! Maybe mine will turn out as good as yours. Is their anything in perticullar I should be aware of as far as replacement parts or recommendations on upgrades? It's just gonna be for joy-rides and make ppl remember how trucks ust to be made .

[fomocoguy]

Great build thread! I recently purchased a 68 swb with a 300 and three on the tree, engine had a bad headgasket so I pulled it yesterday, hopefully I can finish disassembly tomarrow and send it to the machine shop. This will be my first build and your post have offered great info! Maybe mine will turn out as good as yours. Is their anything in perticullar I should be aware of as far as replacement parts or recommendations on upgrades? It's just gonna be for joy-rides and make ppl remember how trucks ust to be made .

Glad you found this helpful! I honestly learned a lot about these engines during this build. I can tell you that for starters Offenhauser claims over 100hp gain from stock figures by installing a 4 barrel carb, manifold, cam change, and header. I went with the split efi manifolds from the FI engine just because they flow great, fit nice, and I hate headers. There is a lot you can do to help it breath (bigger valves, clearancing around the exhaust valve, light porting, etc). You just have to figure out what your end goal for your engine is and do what you feel necessary to get you there. I wanted big low end torque, so I left the valves alone but opted to de-shroud the exhaust valve and did a lot of smoothing in the ports. I also used pistons to bring me up to 9.0:1 cr and got my quench down to ~.038 (using a .021 copper head gasket) to help fight spark knock. Last I advanced the cam timing, which boosts low end. If you want yours to rev past 4500 rpm, you'll want to do things a bit different. I just want to be able to pull the heft of my 5500# truck plus an occaisional load, so big torque was my focus.

[gregamorton]

sounds good with the way you built it. What size pipe and what kind of muffler did you go with?

[fomocoguy]

sounds good with the way you built it. What size pipe and what kind of muffler did you go with?

Well, the factory efi y-pipe is 2.5", but I had a thrush welded muffler (flowmaster knock off) laying around so I just stuck it on there. The muffler is only 2.25". I'm thinking that once it's in the truck I will increase it to 3" as close to the y as I can and run a single 3" pipe to a 3" version of this thrush muffler, with it dumped just before the axle or possibly turned out in front of the tire and finished off in 4" pipe for that sweet "echo" sound. We'll see. I just keep thinking that 2.5" might have been good for a stock efi engine but may be a bit small for this build.

[austin]

sounds good should pull lots of stumps

 them flowmaster knock-offs sound good acutally im running a hedman header with dual 2.25 exhaust and flowmaster knock offs on my 2 wheel drive people ask me all time if its got a 390

[fomocoguy]

:clap: sounds good should pull lots of stumps

 them flowmaster knock-offs sound good acutally im running a hedman header with dual 2.25 exhaust and flowmaster knock offs on my 2 wheel drive people ask me all time if its got a 390

Thanks! Yeah, I decided to go ahead and order exhaust for it. I got a couple 4 ft lengths of 3" pipe, a 3" Thrush welded muffler, and a few various other parts to put it all together. It will increase right at the y from 2.5" to 3" and have a turn down just after the muffler under the bed. If it's too loud in the cab I'll have it turn out the side.

Tomorrow I'm gonna start taking the truck apart! My goal is to have the 360 out and start prepping the engine bay. I still need to get a clutch for it, but would like to have it all back together by next weekend. We'll see.

[fomocoguy]

For anyone who was following this thread, the engine is completely re-installed and things are being fine tuned. You can follow along in my general crew build thread here: viewtopic.php?f=22&t=33739