Thinking of swapping in a 351w - new internals?

[Whiplash-Smile]

I am worried my 302 block won't handle 7-8 psi especially with a 100 shot.. I decided to pick up a 351w from a 1990 bronco and use the shortblock with my TF Twisted Wedge heads(after I drill them for the larger 351 head bolts) I have a UPR chromo k member and BBK longtube headers, an adjustable weight sfi front damper, Findanza Aluminum flywheel(28oz) and a Moroso 7qt oil pan - I also have a 2.5" cowl hood.

I know I need-

lower intake - (I have the Edelbrock RPM upper)

distributor

oil pump

weights on the flywheel and damper to match the 351 crank balance. Anything else that you guys are aware of? Will the parts I listed above get it done?



I basically was just going to freshen up the block - the motor ran great before the bronco got rearended and actually the moved it around under its own power at my buddies shop - so new bearings and maybe some total seal gapless rings to ensure the boost wasnt ending up in the crankcase I had started talking H beams, SRP pistons and the whole nine yards to my machinist, and he asked how fast I planned to spin it. I had to think about it but realistically only 6k rpms will be where I set my limiter. He said that block would be fine stock and so would the rods and pistons below 10 PSI, just ARP the rods, with ARP studs in the block and balance it. Which brings up my question.. the cost of resizing the rods after pressing in new ARP rod bolts is 50.00 less than a NEW set of Eagle I beams WITH the ARP's already in place..

I think I will spend the extra for the eagle's, should I get new pistons as well? Is there a good set of reasonably priced pistons for the 351w? My machinist said the stock ones would probably be fine..

Sorry so long winded and thanks for your time!

Sam

 

[mwood]

Two thoughts. Do it once, do it right. And, most new pistons are clearenced for valves. Kind of nice when adding a custom cam and non stock valvetrain. Still want to check to be sure though.

PS, be ready for that balancing. It can be cheap and it can be expensive. Depends on the need for extra metal.

 

[Whiplash-Smile]

Yupp I totally agree with the balancing part - I am hoping that with the matched weight Eagles the balancing cost stays fairly low.

I am using the the Trickflow Stage 1 with Cobra 1.7' rockers - should be pretty sedate and keep my powerband low. I am still indecisive on the rods and pistons and for what it is worth I already have heard it regarding the nitrous - I know it isn't needed... BUT IT IS STARING AT ME FROM THE SHELF!

 

[NIKwoaC]

Well, if I was going to throw boost at it, ESPECIALLY if I was also going to spray it, I'd want forged pistons, and the stock 351 pistons are not forged. Of course, it really comes down to the tune as to whether it is going to blow up or not. The forged pistons are really just insurance for a little more wiggle room.

Also, you know that block is not a roller cam block, right?

 

[90lxcoupe]

Why are you running nitrous? Why not just turn the boost up and make it simpler and easier?

Id say a good set of piston and H-beams should be on order. also, you wont have to redrill the TF heads, they are already set for 1/2" headbolts

 

[Whiplash-Smile]

Thanks for the input NikwoaC!
I am not a fan of forged.. they would be high silica(hypereutectic) or cast at that RPM range and powerlevel.

the block is a roller block NOW

 

[Whiplash-Smile]

Why are you running nitrous? Why not just turn the boost up and make it simpler and easier?

Id say a good set of piston and H-beams should be on order. also, you wont have to redrill the TF heads, they are already set for 1/2" headbolts

see above on the nitrous

the boost is about as high as I want it - it is a Powerdyne, so no point in grenading it with that smaller pulley.

Less boost + small shot = less strain on all systems involved(I am using a Snow stage II coupled with an EEC Tuner for detonation control) and I can make changes to either system to get me to the 500hp mark(at least this is what I am telling myself)

I tend to agree that I MAY need pistons and rods - but REALLY wanted to hear from someone who has done this or something similar. Though I welcome all input and only stipulate it SHOULD be educated

90lxcoupe are you sure the Twisted Wedges are 1/2" already?

 

[NIKwoaC]

Thanks for the input NikwoaC!
I am not a fan of forged.. they would be high silica(hypereutectic) or cast at that RPM range and powerlevel.

the block is a roller block NOW

Haha, saying you don't like forged is like a straight guy saying he doesn't like attractive women, he'd rather have his butt-ass ugly.

 

[Whiplash-Smile]

hehe, no I didn't say I don't like forged, I am just not a fan. It isn't necessary in this application(or in about 50% of the applications I see it recommended - case in point) but your analogy made me nearly shoot coffee out my nose

 

[90lxcoupe]

why do you ask for advice? seems to me like you know it all already. You are just asking for trouble with a dual power adder hammering a hyper piston. and yes im sure that the TW heads are half inch, in fact most aluminum heads(every one ive seen) are. Thats why they make those steeped washers that come with head studs. I dont know if head bolts need them because ive never used anything but a headstud.

the nitrous is going to be more abuse on the motor then a few more pounds of boost.

 

[Whiplash-Smile]

Well.. I asked for advice because I was hoping(and still am) that someone that had done this or had first hand knowledge of this would chime in.

I certainly did not want to seem like I would ever question anyone's advice.

That being said, you were dead on accurate with the head bolt's being .5" on the Trickflows!

 

[SMOKEDYA]

Are you worried about putting a strain on the motor?If so ditch the N2O and S/C and go turbo .......Also you will need a new oil pan,351 swap headers,extend the lines connection the fuel rails together,the oil pump will be fine as long as it's for a 351.The 351 will usually handle 600+ at the block.peace












john