I'm working on 2 projects. One being a '76 chevy nova 250 6. The other being a '58 dodge powerwagon. My Nova will be a daily ride and the pw will be a tonka toy (42 inch michelin xzl radials). I want to rebuild my novas engine with an offy 2bbl intake and a holley, but The intake and head are one piece (as i'm sure most of you know). I need an earlier head to put the offy on and I need to know if an early head will fit on a '76 block. also, regarding offy intakes, are they single or dual plane? performance isn't what i'm worried about its sound. dual plane intakes on sixes sound a lot better to me.
Now the PW project. I want to use a 292 chevy engine in it because of the torque. I want the most power and torque I can get out of it while retaining idle quality and reliabilty. What is the max overbore of the 292? what is the best carb n' intake setup for high torque at low rpm?
--Kevin Coleman
You have started a good topic and I am sure you will get a lot of responses. As for the early head on the '76 block, yes it will fit no problem. I believe the Offy intakes are only single plane. On the 292, I would say that a .060" overbore is pretty safe, after that you might get into wall thickness, etc.
Good Luck
Artanisman
Welcome to the inliners. First off I have never seen a dual plane intake for any ChevyL6. the offey & clifford intakes are a single plane. All the early Heads will fit your block.
Now as for a rebuild On any motor If your Not after the Max. It is always better to do a .030 over bore. This way you can always Do a rebuild again later on in life of the block. But if you after the add cubic inch,s for Power go with a .060 over and this still will leave some room for another build If need be.
The offey will give you the better low end to Mid ranger Power and tork. Going with a RV style cam or nothing more then a 500-550 lift hyd. cam. A cam with a lobe seperation Of 114,112,110 anything less will give a Much ruffer idle. And will move the power & tork band Higher up the Rpm scale. The Head is your biggest Issue to look at.
Do a nice port clean up a good 3-4 angle valve job.And for a Better add Boost in Head flow is do to a lump port. Even with staying with the stock size Valves. If your still looking to keep the MPGs it is all the better reason to stay with the stock valves. and top it off with dual exhaust.
Keeping all this in mind will work Very well for Both Motors. If you have any other Questions Just fire away. Hope this helps }[oooooo]
twisted,
Good point on the overbore. I might want a few more rebuilds out of these engines so a .030 would be better than a .060. Concerning the PW, MPG is not a priority. With the nova, MPG is a priority. the PW could get 1/8 mpg for all i care. The bed is huge (you could fit a late model chevy bed inside it), so I can add aux tanks for better range.
Regarding exhaust sound, I was told by a friend with a 73 nova l6 that he had a dual plane intake. he had a single smithys glasspack and it sounded really nice and mellow. wheather he is misinformed about his intake or not i don't know. does a 250/292 sound "good". (yeah i know everyone's definition of "good" is different) Is it mellow?
--Kevin Coleman
yeah they both sound good and now matter how you build them they all sound different. Well I think someone has misinformed him to what he has for a intake. I don't even think it ispossable to build a dual plane intake for our L6s because of the shared Ports. Even my custom built 3x4 tunnel Ram intake is of single plane. He could have dual exhaust tide into one. }[oooooo]