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?