[tmnd777]

Hi, I need some suggestions for engine displacement, intake and a cam recommendation. I’ve not found a 67 Chevelle yet, so I’m building a late 60’s early 70’s gasser style hot rod using a ’51 Chevy BelAir 2 door hardtop. Planning on a straight axle front, ladder bar 3.73 gear rear and a TKO 600 (2.87 first/0.64 fifth). Need enough grunt to take it to the strip every now and then, bolt on some slicks, uncork the fenderwell headers and make some respectable passes. Want to be able to drive to different car events & living in Texas, it needs to be able to run an AC compressor mounted not so noticeably on an Alan Grove low mount bracket.

Starting to gather engine parts & bought a pair of GM aluminum #14011077 castings – C port exhaust, 2.25 intakes with gasket matched intake ports. I know there are better heads, but these were reasonable and have the right look (winters snowflake). I have a chance to purchase an Offy tunnel ram with 2 Holley 450 cfm carbs, is this streetable? I’d love to find a cross ram, but that may be out of my price range. Heck if I spent a lot on induction, I’d be inclined to run a blower, but would probably only run a 6-71 cause I think that fits the look better than a polished latter style huffer. What about displacement? I was thinking about getting a Mark IV 454 truck block and putting a 496 forged rotating assembly with maybe 10.2 CR in it. What about cam recommendations? I have a set of solid roller lifters I got with the heads, but I don’t have to use them.

Thanks for your help. Dan

 

[R66SS427]

Dan, be careful with those heads. I think they are the ones that are famous for tearing the rocker studs out with alot of valve spring pressure. They might fetch enough from a resto guy to buy some tougher heads. JMHO. Good luck with your project, I LOVE those old gassers. :thumbsup:

 

[ddeennis]

tunnel ram- run some vacuum secondary carbs and if you go that route use at least 750 carbs, this allows a weaker signal in the primary and gives you control over the secondary opening rate.

i put 600 holleys on my 468,11.7 to1, solid roller cam engine 685 lift 268@.050" and the secondary opening rate was to fast even with a black spring, signal was just to strong, i swapped them out for 2 750 carbs and problem was solved, by the way i ran the same e.t. and mph with both sets of carbs.

i putting together right now a 468,10.7 to 1, rectangle port combo (325cc runners) i'm going to try the 600's again, my thinking is the big ports and low compresion are going to hurt velocity and maybe the carb signal thru the primary's might be weaker and the secondary's wont come on near as strong.

of course i could be wrong, in that case i will throw the 750 carbs back on.

 

[Tom Mobley]

watch out for the Holley mech secondary carbs with no sec accelerator pump, these are being sold as a kit with the TR manifolds. mech sec, no pump, guess what happens when you nail the throttle? A couple 600s like the old #1850 are good.

 

[427L88]

Dan, be sure to use the extra long rocker studs in those. We actually double helicoiled some 074's after they pulled an exhaust rocker arm boss clean off the head. They were extra long threaded ARPs studs. A MUST HAVE!

Use the roller lifters with a mild pro street style SR cam. If they're in good shape that is. Lunati makes a SR version of my old Ultradyne short track cam, and it would be a dandy in 496, with peak HP at around 6300 is all. Specs out at 243/251@.050"/.660" on a 112LSA.

 

[U00tlc5]

I use two 1850 600's on my small block tunnel ram and have to give them a big thumbs up! The throttle response really suprised me how crisp it is.

Tom

 

[bracketchev1221]

You can use the heads you have, they are good heads. But I would grind the fin out of the exhaust. This was the only difference between the c port and more desired D port head. I had to match a head for my dad, when he blew up his motor and that was what I did.

 

[forcd ind]

i have a vertex mag if your interested, was rebuilt in 2006, really give you that look, lol
PM me if your interested

 

[tmnd777]

Thanks to all for the help and ideas. I'm enjoying gathering pieces for this project.

 

[mrpaticular]

A place in Grand Rapids, Mi. has the old Hilborn Injection. Talk about getting attention!!

 

[tmnd777]

The Hilborn injection would be cool, but I'm not sure I could get it to run right on the street unless I did an EFI conversion.

Got an old GM aluminum square port high rise intake I may use just to get it running, and then figure out where to go from there.