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.
