88stangaruu

I got some good 1968 302 truck connecting rods and im thinking of prepping them, polishing the shafts and having them magnafluxed and shot peened. How much stronger is this going to make them? Its going to be a mild small block im sticking them in with a little nitrous on it.

Im also going to use ARP wave loc bolts.

88stangaruu

Any body have any idea how much stronger these are going to be?

88stangaruu

Still no one?

Alright...well i guess ill give some more info on the motor im trying to build. Well im in-between trying to piece two engines together right now. But im concentrating on the 302 for now for a little strip motor.

Ive got a 1969 302 Truck block bored .030 and 0' decked, ive got 1968 Truck rods with Wac loc bolts, TRW forged .030 over forged pistons. A stock dimension cast crank. Im running a custom Iskenderian cam with .542/.542 251/251 @ .050 and 108 lobe center, and thats a solid hydraulic cam. The roller conversion doesnt fit into my budget, i know i could make more power with the roller but its not a street car and isnt driven often. And a rocker stud girdle. Thats with BBK long tube headers with race mufflers on it.

As far as heads go...im going to get some of those Vic Jr knock offs, Procomp cylinder heads and work on the bowls and port match them to my intake, with stainless chevy 2.02/1.60 valves. As for the intake its going to be a Parker Funnelweb and a Barry Grant 650 demon.
As for a power adder im going to be running a Zex 150wet kit. Stock oil pan with windage tray and main girdle. This motor is going to be running out to about 6,500 or so rpm.


As far as my question on the rods though...im just wondering about how much the shot peening is going to add to the strength of the rods, ive already polished them with cartridge rolls. Getting ready to have the little end bushed and the big end honed.

silver91gt

not much, you should be worried about the block though.
stock blocks will spit in half before the internals fail.

88stangaruu

yea, but those old 68-72 blocks arnt the thin wall castings that 5.0's are, so they're a little better, plus the blocks so old, its settled up and the cast in stresses are all out. Im studding and girdling everything, And keeping the rpms conservative will help alot to.

My uncle told me it helps about 50-75hp over stock non-prepped rods.

silver91gt

still, the block will fail before the rods do, unless you are boosted.

88stangaruu

yes, it will fail before the crank does definatly.

But im more concnerned with the rods. Every blown 302 ive ever seen was a rod or rod bolt failure. H beam rods arnt going to fit into the budget, so the best factory rods will have to do, the football bolt, truck rods.

Ive had some people tell me the block will break at 450hp? I know they cant possibly be serious, cause ive personally seen turbo'd/ nitrous mustangs running close to 550-650hp at the crank on factory 302 blocks, but they only revved to the 5800-6,500 range and the turbo'd ones were daily driven 10 sec cars, i dont know the guy personally but ive mulled over his car for about 2 hours at the local Sonic's car show one night, asking him every question under the sun. Ive heard everything between 450hp-650-700hp depending on the year of the block, so personally im thinking lots of this has to do with internet myth adding or subtracting to the problems, like the myth about the 347 being an oil eater, that problem was blown totally out of proportion. Ive personaly seen one 302 block break, it was a 95 cast roller block that was bored .040, but it had a damn NX 250hp 2 stage on it. Hanging around racers at the drag strip, ive heard that prior to 1978, the 302 blocks main webbing was much thicker and beefier than the much thinner walled 1978+ blocks. Because after 1978 Ford lightened the 302 up close to 40lbs with their new thin walled casting technology. Ive also heard thats why the 351C is so **** to cracking, because they're cast in the thin wall technique.

I mean everything im doing, its not nothing extreme or anything, they're are lots of guys on here running much more radical set ups with later 85+ blocks and theyre all lasting. And thats under 6,200 or so. And im still contemplating the nitrous right now, im not totally sold on it and may not use it. Everyones told me to keep the rpm's conservative and it'll last.

hellas85stang

i run a 70 302 block in my 85 stang..60 over runs cool...0 decked 10.5 comp and edelbrock rpm heads inatke,520 lift 230@50 110-106ls andheaders,hei for ford..less wires....nitrous 100 shot..stock reconditioned rods kb hypers domes...good for 3 yrs so far...my old heads i redid into hi perf big valves arecollecting dust since edelbrocks went on but older blocks aregr8///