Originally Posted by AndyF
Originally Posted by cudaerik
I'm currently in the planning stage of building a 400 stroker (4.250 stroke) for my 69 Roadrunner 5 speed (TKX) .
I would like to hear opinions and suggestions when it comes to selecting a camshaft and lifters for this build. The goal is to build a radical NA street engine that takes full advantage of the TF270 heads with 10.8:1 compression and a hydraulic roller (HR) camshaft.
I'm looking for some advice when it comes to how much camshaft / spring that I would need to take full advantage of theTF270's at the same time as it needs to survive on the street for at least a couple of summers:-)) The engine will be built around the following components: 230 casting 400 block (thick web), 4.25" stroker kit, TF270 heads, Indy 400-3 intake that will be ported and matched to the TF270's by Wilson Manifolds, Holley 1050cfm carburetor, Harland sharp 1:6 rocker arms, TTI 2 1/8" step headers. I'm currently looking at a HR camshaft with the following spec: 266/270 @ .050", .629/.635" lift with 1:6 rockers, 108LSA, spring pressure closed 155#@1.880" open 415#@.650" My question is really if this cam / spring combo will survive on the street? Will a HR lifter with its weight support the powerband of a camshaft and head combo like this? If I go HR what would be the best HR lifter to use in this combo? Is a solid roller an alternative? Would a solid roller survive on the street idling around 1000-1500RPM?


I don't think it is possible to take full advantage of the TF270 heads with a Dominator carb in a street car that has a 5 speed OD transmission. I just don't think any engine builder can do that. A Dominator carb and a big cam will not work in a heavy B body car with a 5 speed manual transmission. You'll be dumping raw fuel out the tail pipes if you drive that combination on the freeway in overdrive. Any camshaft big enough to take full advantage of a TF270 heads and a Dominator carb will have too much overlap to play well with an OD transmission on the freeway.

You need to rethink your combination and/or your goals.


Thanks for getting back to me and sharing your knowledge. What started this new engine project is the engine that i currently got in my 70 Cuda 5 speed which is also a 400 low deck stroker with 4.15" stroke, this engine is just shy of 600hp with a cnc ported eddy heads, 4150 victor jr intake, Holley ultra XP 850 cfm carb, HR camshaft with 252//258@.050 ground on 110 degree LSA and .576" lift with 1:6 rocker arms. This engine is really street friendly and it idles fine at 900 RPM and leaving from 0 in a stop light is no problem with plenty of torque. With this engine in mind I really want and feel that I can trade off some of the street friendly manners in the search for 750hp with the new TF270 based build. What I get out from your comment is really that it's not worth messing around with the TF270's if I'm only going to put a cam in the 240-250 range in it, explain and let me know if I'm wrong. I already have an engine with a cam in the high 250 range and It has manners so I can use it as a daily driver to work if I want . What makes the TF270 engine combo that I previously described so useless? I totally see your point when it comes to the 1050 cfm dominator on the freeway but would a Holley efi system help it? Is it the combination of duration, lift and 108LSA that makes this combo so useless? How can my current engine feel so mild and two "sizes" up on the cam be totally useless? Obviously I'm missing out on something here and I would really appreciate it if you or someone else with greater experience than myself would let me know.

1970 Plymouth Cuda, 512cid on 230 400 block, 5 speed manual.(TKO 600)
1970 Dodge Charger 500, 446cid, 5speed manual.(TKO 600)
1969 Plymouth Roadrunner, 383cid, 5speed manual (Tremec TKX)